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PLANT-BREEDING 


(Slartien^rait  Scries 


The  Horticulturist's  Rule-Book 
Plant-Breeding 


PLANT-BREEDING 


BEINa   FIVE  LECTURES  UPON  THE 

AMELIORATION  OF  DOMESTIC 

PLANTS 


L.  H.  BAILEY 


THE   MACMILLAN   COMPANY 

LONDON:  MACMILLAN  &  CO.,  Ltd. 
1897 

All  rights  reserved 


Copyright,  1895, 
By   L.    II.   BAILEY. 


Set  up  and  electrotyped  December,  1895.     Reprinted 
April,  1896;  August,  1897. 


Norbjooti  Press 

J.  S.  Cushing  &  Co.  -  Berwick  &  Smith 
Norwood  Mass.  U.S.A. 


p 

^ 


#u 


PREFACE. 


There  is  no  subject  associated  with  the  care 
of  plants  respecting  which  there  is  so  much  mis- 
apprehension and  imperfect  knowledge,  as  that 
of  the  origination  of  new  forms.  Most  of  the 
scattered  writing  touching  it  treats  the  subject 
as  if  all  our  knowledge  of  the  matter  were  and 
must  be  derived  wholly  from  experiment.  It 
therefore  recites  examples  of  how  this  and  that 
new  form  has  come  to  be,  and  has  made  little 
attempt  to  discover  the  fundamental  causes  of 
the  genesis  of  the  novelties.  Horticulturists 
commonly  look  upon  each  novelty  as  an  isolated 
fact,  whilst  we  ought  to  regard  each  one  as  but 
an  expression  of  some  law  of  the  variation  of 
plants.  It  is  the  common  notion,  too,  to  con- 
sider any  type  of  plant  to  be  essentially  a  fixed 
entity,  and  to  regard  any  marked  departure  from 
the   type    as   a  phenomenon    rather    more  to  be 


till 


Vi  PREFACE. 

wondered  at  than  to  be  explained.  It  is  evident, 
however,  that  one  cannot  understand  the  pro- 
duction of  new  varieties  until  he  has  grasped 
some  of  the  fundamental  principles  of  the  on- 
ward progression  of  the  vegetable  kingdom. 
Any  attempt,  therefore,  to  explain  the  origin  of 
garden  varieties,  and  the  methods  of  producing 
them,  must  be  at  the  same  time  a  contribution 
to  the  literature  of  the  philosophy  of  organic 
evolution. 

I  do  not  know  of  any  explicit  and  sustained 
attempt  to  account  for  the  evolution  of  all  gar- 
den forms,  and  I  have  therefore  brought  together 
in  this  volume  the  subject-matter  of  various 
lectures  which  I  have  been  in  the  habit  of 
giving  before  my  students.  The  first  and 
third  lectures  were  newly  elaborated  the  present 
summer  for  two  addresses  before  the  class  in 
biology  which  came  together  at  the  University 
of  Pennsylvania,  under  the  auspices  of  the 
American  Society  for  the  Extension  of  Univer- 
sity Teaching.  The  second  lecture  was  first 
presented  before  the  Massachusetts  State  Board 
of  Agriculture,  in  Boston,  December  1,  1891. 
In  April,  1892,  it  was  republished;  with  a  bibli- 


PREFACE.  Vll 

ograpliy  of  the  subject,  by  the  Rural  Publishing- 
Co.,  under  the  title,  "  Cross-Breeding  and  Hybrid- 
izing." This  publication  is  now  out  of  print. 
I  have  made  no  attempt  to  collect  lists  or  cata- 
logues of  varieties,  but  have  endeavored  to  make 
very  brief  statements  of  some  of  the  underlying 
principles  of  the  amelioration  of  plants,  with  only 
sufficient  examples  to  fix  them  in  the  mind. 

I  hope  that  teachers  of  horticulture  and  botany 
may  find  the  book  useful  in  their  classes.  When 
it  is  necessary  to  abridge  the  instruction  or  to 
present  it  to  untrained  students,  only  Lectures 
III.  and  V.  may  be  used,  for  these  contain  the 
matters  of  greatest  demonstrative  importance. 

L.  H.  Bailey. 

Cornell  University, 
Ithaca,  N.Y.,  September  1,  1895. 


CONTENTS. 


LECTURE   I. 

PAGE 

The  Fact  and  Philosophy  of  Variation         ...         1 

I.  The  Fact  of  Individuality 2 

The  seed-individual. 
The  hud-individual. 

II. 


TJie  Causes  of  Individual  Differences 

8 

a.  Fortuitous  variation    .... 

9 

b.  Sex  as  a  factor  in  the  variation  of  plants 

11 

c,  Physical  environment  and  variation    . 

12 

1.  Variation  in  food  supply 

16 

2.  Variation  in  climate     . 

24 

3.  Change  of  seed.     Bud-variation 

28 

d.  Struggle  for  life  a  cause  of  variation  . 

29 

The  Choice  and  Fixation  of  Variations 

.      31 

III. 


LECTURE   II. 

The  Philosophy  of  the  crossing  of  Plants,  consid- 
ered in  Reference  to  their  Improvement  under 
Cultivation        ........       39 

I.    The  Struggle  for  Life 39 

II.    The  Division  of  Labor         .....       42 

III.    The  Limits  of  Crossing        .         „         .  44 

ix 


CONTENTS. 

IV.  Function  of  the  Cross  .... 

a.  The  gradual  amelioration  of  the  type 
6.  Change  of  seed  and  crossing 
c.  The  outright  production  of  new  varieties 

V.  Characteristics  of  Crosses   .... 
VI.    Uncertainties  of  Pollination 

Conclusion 


LECTURE   III. 
How  Domestic  Varieties  Originate 

I.  Indeterminate  Varieties        .... 
II.  riant-breeding     .         .         . 

Rule    1.   Antagonistic  features 

Rule    2.    Quickest  results  in  the  most  variable 

groups  

Rule    3.   Breed  for  one  thing  at  a  time   . 

Rule    4.    Contradictory  attributes  . 

Rule    5.   Characters  of  the  entire  plant  most 

important      .... 
Rule    G.   Plants  differ  in  hereditary  power 
Rule    7.    Less  marked  variations  more  impor 

tant 

Rule    8.    Crossing  a  means,  not  an  end  . 
Rule    0.    Choice  of  parents  to  a  cross 
Rule  10.    The  ideal  should  be  mental 
Rule  11.    Seek  to   produce  variation    in    the 

desired  direction  . 
Rule  12.    Watch  for  bud- varieties    . 
Rule  13.    Progress  lies  in  selection  . 
Rule  14.    The  type  is  kept  up  to  standard  by 

continued  selection 
Rule  15.    The  best  final  results  are  to  be  ob 

tained  by  high  tillage  and  intelli 

gent  selection 


CONTENTS. 


XI 


III.  Specific  Examples 

The  dewberry  and  blackberry 
The  apple 

Beans        .... 
Cannas     . 


PAGK 

129 

129 
131 
135 
140 


LECTURE   IV. 


Borrowed  Opinions  ;  being  Extracts  from  the  Writ- 
ings of  B.  Verlot,  E.  A.  Carriere,  and  W.  O. 
Focke  ......... 

I.  VerloVs  Classification  of  Varieties  of  Ornamen- 
tal Plants 

II.   Carriere1  s  Account  of  Bad- varieties    . 

1.  General  remarks  upon  bud- variation  . 

2.  List  of  bud-varieties 

III.  Focke's    Discussion    of    the    Characteristics    of 
Crosses         ....... 

i.  The  simple  primary  cross   .... 
Proposition  1.  Similarity  of  crossed  off- 
spring . 
Proposition  2. 

offspring 
Proposition  3. 

brids    . 
Proposition  4.  Comparative    fertility  of 

hybrids 

Proposition  5 

offspring 

ii.  The  progeny  of  crosses       .... 

1.  Progeny  of  crosses  with  their  own 

pollen 


Dissimilarity   of    crossed 
Vegetative  powers  of  hy- 


Malformations  in  hybrid 


143 

143 

153 

154 
176 

215 
215 

215 

221 

225 

228 

237 

237 

238 


Xll  CONTENTS. 

PAGE 

2.  Derivative  hybridization    of    crosses 

with  the  parent  forms     .         .         .     242 

3.  Hybrids  of  several  species  .         .         .     244 

a.  Triple  hybrids      .        .         .         .244 

b.  Hybrids  of  four  to  six  species      .     240 

c.  Crosses  of  plants  grown  together    247 
iii.  Cross-breeds  and  hybrids  ....     247 


LECTURE   V. 

Pollination  ;  or  How  to  Cross  Plants  ....     252 

I.    The  Structure  of  the  Flower       .         .         .         .252 
II.  Manipulating  the  Flowers  .  265 

GLOSSARY .282 

INDEX       . 286 


PLANT-BREEDING. 

LECTURE   I. 

THE  FACT   AND   PHILOSOPHY  OF   VARIATION. 

There  is  no  one  fact  connected  with  horticult- 
ure which  so  greatly  interests  all  persons  as  the 
existence  of  numerous  varieties  of  plants  which 
seem  to  satisfy  every  need  of  the  gardener. 
Whence  came  all  this  multitude  of  forms?  What 
are  the  methods  employed  in  securing  them  ?  Are 
they  simply  isolated  facts  or  phenomena  of  gar- 
dening, or  have  they  some  relation  to  the  broader 
phases  of  the  evolution  of  the  forms  of  life? 
These  are  some  of  the  questions  which  occur  to 
every  reflective  mind  when  it  contemplates  an 
attractive  garden,  but  they  are  questions  which 
seem  never  to  be  answered.  Whatever  attempt 
the  gardener  may  make  at  answering  them  is 
either  befogged  by  an  effort  to  define  what  a  vari- 
ety is,  or  else  it  consists  in  simply  reciting  how  a 
few  given  varieties  came  to  be  known.     But  there 

B  1 

HWPER7T  UUMJir 


2  FACT   AND   PHILOSOPHY   OF    VARIATION. 

must  be  some  fundamental  method  of  arriving  at 
a  conception  of  how  the  varieties  of  fruits  and 
flowers  and  other  cultivated  plants  have  origi- 
nated. If  there  is  no  such  method,  then  the 
origination  of  these  varieties  must  follow  no  law, 
and  the  discussion  of  the  whole  subject  is  fruit- 
less. But  we  have  every  confidence  in  the  con- 
secutive uniformity  of  the  operations  of  nature, 
and  it  were  strange  if  some  underlying  principle 
of  the  unfolding  or  progression  of  plant  life  does 
not  dominate  the  origin  of  the  varied  and  in- 
numerable varieties  which,  from  time  unknown, 
have  responded  to  the  touch  of  the  cultivator. 
Let  us  first,  therefore,  make  a  broad  survey  of  the 
subject  in  a  philosophical  spirit,  and,  later,  discuss 
the  more  specific  instances  of  the  origination  of 
varieties. 

I.   The  Fact  of  Individuality. 

There  is  universal  difference  in  nature.  No 
two  living  things  are  exact  counterparts,  for  no 
two  are  born  into  exactly  the  same  conditions  and 
experiences.  Every  living  object  has  individ- 
uality ;  that  is,  there  is  something  about  it  which 
enables  the  acute  observer  to  distinguish  it  from 
all  other  objects,  even  of  the  same  class  or  spe- 
cies. Every  plant  in  a  row  of  lettuce  is  different 
from  every  other  plant,  and  the   gardener,  when 


INDIVIDUALITY.  3 

transplanting  them,  selects  out,  almost  uncon- 
sciously, some  plants  which  please  him  and  others 
which  do  not.  Every  apple  tree  in  an  orchard  of 
a  thousand  Baldwins  is  unlike  every  other  one, 
perhaps  in  size  or  shape,  or  possibly  in  the  vigor 
of  growth  or  the  kind  of  fruit  it  bears.  Persons 
who  buy  apples  for  export  know  that  fruit  from 
certain  regions  stands  the  shipments  better  than 
the  same  variety  from  other  regions ;  and  if  one 
were  to  go  into  the  orchards  where  these  apples 
are  grown,  he  would  find  the  owner  still  further 
refining  the  problem  by  talking  about  the  merits 
of  individual  trees  in  his  orchard.  If  one  were 
to  make  the  effort,  he  would  find  that  it  is  pos- 
sible to  distinguish  differences  between  every  two 
spears  of  grass  in  a  meadow,  or  every  two  heads 
of  wheat  in  a  grain-field. 

All  this  is  equivalent  to  saying  that  plants  are 
infinitely  variable.  The  ultimate  causes  of  all 
this  variation  are  beyond  the  purpose  of  the 
present  discussion,  but  it  must  be  evident,  to 
the  reflective  mind,  that  these  differences  are 
the  means  of  adapting  the  innumerable  indi- 
viduals to  every  little  difference  or  advantage 
in  the  environment  in  which  they  live.  And  if 
the  object  of  variation  is  better  adaptation  to 
the  physical  conditions  of  life,  then  the  same 
motive  must  have  been  present  in  the  circum- 
stances which  determined  the  birth  of  the  indi- 


4         FACT   AND   PHILOSOPHY   OF   VARIATION. 

victual.  The  variation  in  environment,  therefore, 
must  be  the  cause  of  much  of  the  variation  in 
plants,  since  differences  in  plants  Avere  positively 
injurious  if  it  were  possible  for  the  conditions  of 
environment  to  be  the  same. 

If  no  two  plants  are  anywhere  alike,  then  it  is 
not  strange  if  now  and  then  some  departure,  more 
marked  than  common,  is  named  and  becomes  a 
garden  variety.  We  have  been  taught  to  feel 
that  plants  are  essentially  stable  and  inelastic, 
and  that  any  departure  from  the  type  is  an  excep- 
tion and  calls  for  immediate  explanation.  The 
fact  is,  however,  that  plants  are  essentially  un- 
stable and  plastic,  and  that  variation  between  the 
individuals  must  everywhere  be  expected.  This 
erroneous  notion  of  the  stability  of  organisms 
comes  of  our  habit  of  studying  what  we  call 
species.  We  set  for  ourselves  a  type  of  plant  or 
animal,  and  group  about  it  all  those  individuals 
which  are  more  like  this  type  than  they  are  like 
any  other,  and  this  group  we  name  a  species. 
Nowadays,  the  species  is  regarded  as  nothing 
more  than  a  convenient  and  arbitrary  expression 
for  classifying  our  knowledge  of  the  forms  of 
life,  but  the  older  naturalists  conceived  that  the 
species  is  the  real  entity  or  unit  in  nature,  and  we 
have  not  yet  wholly  outgrown  the  habit  of  mind 
which  was  born  of  that  fallacy.  Nature  knows 
nothing  about  species ;   she  is  concerned  with  the 


INDIVIDUALITY.  5 

individual,  the  ultimate  unit.  This  individual  she 
moulds  and  fits  into  the  chinks  of  environment, 
and  each  individual  tends  to  become  the  more 
unlike  its  birthmates  the  more  the  environments 
of  the  various  individuals  are  unlike.  I  would 
impress  upon  you,  therefore,  as  a  fundamental 
conception  to  the  discussion  of  the  general  subject 
before  us,  the  importance  of  the  individual  plant, 
rather  than  the  importance  of  the  species ;  for 
thereby  we  put  ourselves  as  nearly  as  possible  in 
a  sympathetic  attitude  with  nature,  and,  resting 
upon  the  ultimate  object  of  her  concern,  we  are 
able  to  understand  what  may  be  conceived  to  be 
her  motive  in  working  out  the  problem  of  life. 
That  I  may  still  more  forcibly  emphasize  this 
thought,  let  me  recall  to  your  minds  the  fact 
that  the  whole  tendency  of  contemporary  civili- 
zation, in  sociology  and  religion,  is  to  deal  with 
the  individual  person  and  not  with  the  mass. 
This  is  only  an  unconscious  feeling  after  natu- 
ral methods  of  solving  the  most  complex  of 
problems,  for  it  is  exactly  the  means  to  which 
every  organic  thing  has  been  subjected  from  the 
beginning. 

In  looking  for  the  ultimate  unit  or  individuality 
or  personality  in  nature,  we  must  make  a  broad  dis- 
tinction between  the  animal  and  the  plant.  Every 
higher  animal  is  itself  a  unit ;  it  is  one.  It  has 
a  more  or  less  definite  span  of  life,  and  every  part 


6         FACT   AND    PHILOSOPHY    OF   VARIATION. 

and  organ  contribute  a  certain  indispensable  part 
to  the  life  and  personality  of  the  organism.  No 
part  is  capable  of  propagating  itself  independently 
of  the  sex-organs  of  the  animal,  nor  is  it  capable 
of  developing  sex-organs  of  its  own.  If  any  part 
is  removed,  the  animal  is  maimed  and  perhaps  it 
dies.  The  plant,  on  the  contrary,  has  no  definite 
or  distinct  autonomy.  Most  plants  live  an  indefi- 
nite existence,  dependent  very  closely  upon  the 
immediate  conditions  in  which  they  grow.  Every 
part  or  branch  of  the  plant  lives  largely  for  itself, 
it  is  capable  of  propagating  and  multiplying  itself 
when  removed  from  the  parent  plant  or  the  colony 
of  branches  of  which  it  is  a  member,  and  it  de- 
velops sex-organs  and  other  individual  features 
of  its  own.  If  any  branch  is  removed,  the  tree 
or  plant  does  not  necessarily  suffer;  in  fact,  the 
remaining  branches  usually  profit  by  the  removal, 
a  fact  which  shows  that  there  is  a  competition, 
or  struggle  for  existence,  between  the  different 
branches  or  elements  of  the  plant.  The  whole 
theory  and  practice  of  pruning  rest  upon  the  fact 
of  the  individual  unlikenesses  of  the  branches  of 
plants ;  and  these  unlikenesses  are  of  the  same 
kind  and  often  of  the  same  degree  as  those  which 
exist  between  different  plants  which  are  grown 
from  seeds.  That  is,  the  brandies  of  a  Crawford 
peach  tree,  for  example,  differ  amongst  themselves 
in  size,  shape,  vigor,  productiveness,  and  season  of 


BUD-INDIVIDUALS.  7 

maturity,  the  same  as  any  two  or  more  separate 
Crawford  trees,  or  any  number  of  trees  of  other 
varieties,  differ  the  one  from  the  others.  If  any 
one  of  these  branches  or  buds  is  removed  and  is 
grown  into  an  independent  tree,  a  person  could 
not  tell  —  if  he  were  ignorant  of  its  history  —  if 
this  tree  were  derived  from  a  branch  or  a  seed. 
This  proves  that  there  is  no  essential  unlikeness 
between  branches  and  independent  plants,  except 
the  mere  accident  that  one  grows  upon  another 
branch  or  plant  whilst  the  other  grows  in  the 
ground.  But  the  branch  may  be  severed  and 
grown  in  the  ground,  and  the  seedling  may  be 
pulled  up  and  grafted  on  the  tree,  and  no  one 
can  distinguish  the  different  origins  of  the  two. 
And  then,  as  a  matter  of  fact,  a  very  large  pro- 
portion of  our  cultivated  plants  are  not  distinct 
plants  at  all,  in  the  sense  of  being  different  crea- 
tions from  seeds,  but  are  simply  the  results  of 
the  division  of  branches  of  one  original  plant  or 
branch.  All  the  fruit  trees  of  any  one  variety 
are  obtained  from  the  dividing  up  and  multiplica- 
tion of  the  branches  of  the  first  or  original  tree. 

You  are  now  curious  to  know  how  this  orig- 
inal tree  came  to  be,  and  this  I  hope  to  tell 
you  before  I  am  done  ;  but  for  the  present,  let 
me  impress  it  upon  you  that  it  is  equally  possi- 
ble for  it  to  have  come  from  a  seed,  or  to  have 
sprung  from   a   branch  which  some   person   had 


8         FACT   A^D   PHILOSOPHY    OF    VARIATION. 

noticed  to  be  very  different  from  the  associated 
branches  in  the  tree-top.  In  other  words,  the 
ultimate  unit  or  individual  in  growing  plants  is 
the  bud  and  the  bit  of  Avood  or  tissue  to  which  it 
is  attached  ;  for  every  bud,  like  every  seed,  pro- 
duces an  offspring  which  can  be  distinguished 
from  every  other  offspring  whatsoever. 

II.    The  Causes  of  Individual  Differences. 

We  have  now  gotten  back  to  the  starting-point, 
to  that  unit  with  which  nature  begins  to  make 
her  initial  differences  or  individualities  ;  that  is, 
to  the  point  where  variations  arise.  This  unit 
is  the  bud  and  the  seed,  —  one  sexless,  or  the 
offspring  of  one  parent ;  the  other  sexual,  or  the 
offspring  of  two  parents.  Now,  inasmuch  as 
the  horticultural  variety  is  only  a  well-marked 
variation  which  the  gardener  has  chanced  to 
notice  and  to  propagate,  it  follows  that  the  only 
logical  method  of  determining  how  garden  vari- 
eties originate  is  to  discover  the  means  by  which 
plants  vary  or  differ  one  from  another. 

There  is  probably  no  one  fact  of  organic  nature 
concerning  the  origin  of  which  modern  philoso- 
phers are  so  much  divided  as  the  genesis  or 
reasons  for  the  beginnings  of  variations  or  dif- 
ferences. It  seems  to  be  an  inscrutable  problem, 
and  it  would  be  useless,  therefore,  for  us  to  at- 


FORTUITOUS    VARIATION.  9 

tempt  to  discover  these  ultimate  forces  in  the 
present  hour.  Still,  we  must  give  them  sufficient 
thought  to  enable  us  to  satisfy  our  minds  as  to 
how  far  these  variations  may  be  produced  by 
man  ;  and,  in  doing  this,  we  must  discover  at 
least  the  underlying  philosophy  of  plant  variation. 
It  is  the  nature  of  organisms  to  be  unlike  their 
parents  and  their  birthmates.     Why  ? 

a.    Fortuitous    Variation. 

It  will  probably  never  be  possible  to  refer  every 
variation  to  a  distinct  cause,  for  it  is  probable  that 
some  of  them  have  no  antecedent.  If  we  con- 
ceive of  the  forms  of  life  as  having  been  created 
with  characters  exactly  uniform  from  generation 
to  generation,  then  we  should  be  led  to  look  for 
a  distinct  occasion  or  cause  for  every  departure 
from  the  type  ;  but  we  knoAv,  as  I  have  already 
pointed  out,  that  heredity  by  its  very  nature  is 
not  so  exact  as  to  carry  over  every  attribute,  and 
no  other,  of  the  parent  to  the  offspring.  Elas- 
ticity, plasticity,  is  a  part  of  the  essential  consti- 
tution of  all  organic  beings.  There  is  probably 
no  inherent  tendency  in  organisms  towards  any 
ultimate  or  predetermined  completion  of  form,  as 
the  older  naturalists  supposed,  but  simply  a  laxity 
or  inclefiniteness  of  constitution  which  is  expressed 
in   numberless   minor    differences    in    individuals. 


10      FACT   AND   PHILOSOPHY   OF   VARIATION. 

That  is,  some  variation  is  simply  fortuitous,  an 
inevitable  result  of  the  inherent  plasticity  of 
organisms,  and  it  has  no  immediate  inciting 
cause.  If  we  were  to  assume  that  every  minor 
difference  is  the  result  of  some  immediate  cause, 
then  we  should  expect  every  individual  plant  or 
animal  to  till  some  niche,  to  satisfy  some  need,  to 
produce  the  definite  effect  for  which  the  cause 
stands.  But  it  is  apparent  to  one  who  contem- 
plates the  operations  of  nature  that  very  many  — 
certainly  more  than  half  —  of  the  organisms  which 
are  born  are  wholly  useless  in  the  struggle  for 
life  and  very  soon  perish.  From  these  fortuitous 
variations  nature  selects,  to  be  sure,  many  indi- 
viduals to  be  the  parents  of  other  generations 
because  they  chance  to  be  fitted  to  live,  but  this 
does  not  affect  the  methods  or  reasons  of  their 
origin.  It  is  possible  that,  whilst  many  of  these 
mere  individual  differences  have  no  direct  and 
immediate  cause,  they  may  still  be  the  result  of  a 
devious  line  of  antecedent  causes  long  since  so 
much  diffused  and  modified  that  they  will  remain 
forever  unrecognizable  ;  but  even  if  so,  the  fact 
still  remains  that  these  present  differences  or 
variations  may  be  purposeless,  and  it  is  quite  as 
well  to  say  that  they  exist  because  it  is  a  part 
of  the  organic  constitution  of  living  things  that 
unlike  produces  unlike. 


SEX   AND    VARIATION.  11 

b.    Sex  as  a  Factor  in  the  Variation  of  Plants. 

All  plants  have  the  faculty,  either  potential  or 
expressed,  of  propagating  themselves  by  means 
of  buds,  or  asexual  parts.  This  is  obviously  the 
cheapest  and  most  direct  possible  method  of  propa- 
gation for  many-membered  plants,  since  it  requires 
no  special  reproductive  organization  and  energy, 
and,  as  only  one  parent  is  concerned  in  it,  there 
is  none  of  the  risk  of  failure  which  resides  in  any 
mode  of  propagation  in  which  two  parents  must 
find  each  other  and  form  a  union.  There  must 
be  some  reason,  therefore,  for  the  existence  of 
such  a  costly  mechanism  as  sex  aside  from  its  use 
as  a  mere  means  of  propagation.  It  may  be  said 
that  it  exists  because  it  is  a  means  of  more  rapid 
multiplication  than  bud-propagation,  but  such  is 
not  necessarily  the  fact.  There  are  many  plants 
which  produce  buds  as  freely  as  they  produce 
seeds  ;  and  then,  if  mere  multiplication  were  the 
only  destiny  of  the  plant,  bud-production  would 
no  doubt  have  greatly  increased  to  have  met  the 
demand  for  new  generations.  The  only  reason 
for  the  existence  of  sex  in  the  vegetable  world 
seems  to  be  the  need  for  a  constant  rejuvenation 
and  modification  of  the  offspring  by  uniting  the 
features  of  two  individuals  into  one.  There  thus 
arises  from  every  sexual  union  a  number  of  new 
or  different  forms  from  which  nature  may  select 


12      FACT   AND   PHILOSOPHY    OF    VARIATION. 

the  best,  —  that  is,  those  best  fitted  to  live  in  the 
conditions  in  which  they  chance  to  be  placed. 
But  whilst  sex  is  undoubtedly  one  of  the  most 
potent  sources  of  present  unlikenesses,  it  is  not 
necessarily  an  original  cause  of  individual  differ- 
ences, since  the  two  parties  to  any  sexual  con- 
tract must  be  unlike  before  they  can  produce 
unlike.  When  once  the  initial  unlikenesses  were 
established,  every  new  sexual  union  would  pro- 
duce new  combinations,  so  that  now,  when  every 
new  form,  from  whatever  source  it  appears,  comes 
into  existence,  there  are  other  intimately  related 
forms  with  which  it  may  cross.  This  state  of 
things  has  existed  to  a  greater  or  less  degree  from 
the  moment  sex  first  appeared,  so  that  the  organic 
world  is  now  endlessly  varied  as  the  result  of  a 
most  complex  ancestry. 

The  variety  which  sexual  union  has  introduced 
into  the  world  performs  such  an  important  part  in 
the  evolution  of  the  forms  of  plants,  and  the  prob- 
lems which  it  presents  are  so  complex,  that  I  shall 
leave  the  whole  subject  for  an  independent  dis- 
cussion (Lecture  II.). 

r 

c.    Physical  Environment  and  Variation. 

Every  phase  and  condition  of  physical  circum- 
stances, which  are  not  absolutely  prohibitive  of 
plant   life,    have    plants    which    thrive    in    them. 


ENVIRONMENT   AND    VARIATION.  13 

Every  soil  and  climate,  every  degree  of  humidity, 
hills,  swamps,  and  ponds,  —  every  place  is  filled 
with  plants.  Even  the  trunks  and  branches  of 
trees  support  other  plants,  as  epiphytes  and  para- 
sites. That  is,  plants  have  adapted  themselves  to 
every  physical  environment ;  or,  to  turn  the  propo- 
sition around,  every  physical  environment  pro- 
duces adaptive  changes  in  plants.  There  are 
those,  like  Weismann  and  his  adherents,  who 
contend,  from  purely  speculative  reasons,  that 
these  changes  do  not  become  hereditary  or  perma- 
nent until  they  have  influenced  a  certain  physio- 
logical substance  which  is  assumed  to  reside  in 
the  reproductive  regions  of  the  organism,  and 
that  all  those  changes  which  have  not  yet  reached 
this  germ-plasm  are,  therefore,  lost,  or  die  with 
the  organism.  It  is  not  necessary  to  combat  this 
philosophy,  for  Ave  know,  as  a  matter  of  common 
horticultural  experience,  that  every  change  or  va- 
riation in  any  organism  —  unless  it  proceeds  from 
mere  accident  or  mutilation  —  may  become  heredi- 
tary or  be  the  beginning  of  a  new  variety ;  it  is 
only  necessary,  therefore,  for  the  Weismannians  to 
assume  —  as  they  are  always  ready  to  do  —  that 
any  variation  which  has  become  fixed  or  permanent 
has  already  affected  the  germ.  Their  assumption 
needs  only  another  assumption  to  prove  it,  and, 
therefore,  when  we  are  considering  merely  plain 
matters  of  fact  and  experience,  we  need  give  little 


14      FACT   AND   PHILOSOPHY   OF    VARIATION. 

attention  to  the  subtleties  of  this  Neo-Darwinian 
philosophy. 

Weismann  teaches  that  "acquired  characters," 
or  those  variations  which  first  appear  in  the  life- 
time of  the  individual  because  of  the  influences  of 
environment,  are  lost,  because  they  have  not  yet 
affected  the  reproductive  substance.  But  if  these 
characters  are  induced  by  the  effect  of  impinging 
environment  during  two  or  more  generations,  they 
may  come  to  be  so  persistent  that  the  plant  can- 
not throw  them  off,  and  they  become,  thereby,  a 
part  of  the  hereditary  and  non-negotiable  prop- 
erty of  the  species.  Noav,  it  is  apparent  that  in 
one  or  another  of  the  generations  which  are  thus 
acted  upon  by  the  environment,  there  must  be  a 
beginning  towards  the  fixing  or  hereditably  per- 
manency of  the  new  form,  and  we  might  as  well 
assume  that  this  beginning  takes  place  in  the  first 
generation  as  in  the  last,  since  there  can  be  no 
proof  that  it  does  not  take  place  in  either  one. 
The  tendency  towards  fixity,  if  it  exists  at  all, 
undoubtedly  originates  at  the  very  time  that  the 
variation  itself  originates,  and  it  is  only  sophistry 
to  assume  that  the  form  appears  at  one  time  and 
the  tendency  towards  permanence  at  another  time. 
Since  plants  fit  themselves  into  their  circumstances 
by  means  of  adaptive  variations,  we  must  con- 
clude that  all  adaptive  variations  have  the  power 
of  persisting,  upon  occasion. 


NATAL   AND   POST-NATAL   VARIATION.         15 

All  these  remarks,  whilst  somewhat  abstruse, 
have  a  most  important  bearing  upon  the  phi- 
losophy of  the  origin  of  garden  varieties,  because 
they  show,  first,  that  changes  in  the  conditions  in 
which  plants  grow  introduce  modifications  in  the 
plants  themselves,  and  second,  that  wherever  any 
modification  occurs  it  is  probable  that  it  may  be 
fixed  and  perpetuated. 

It  is  necessary,  at  this  point,  that  Ave  distin- 
guish between  natal  and  post-natal  variations ; 
that  is,  between  those  variations  which  are  born 
with  plants,  and  those  which  appear,  as  a  result  of 
environment,  after  the  plant  has  begun  to  grow. 
It  is  commonly  assumed  that  the  form  and  general 
characters  of  the  plant  are  already  determined  in 
the  seed,  but  a  moment's  reflection  will  show  that 
this  is  far  from  the  truth.  One  may  sow  a  hun- 
dred selected  peas,  for  instance,  all  of  which  majr 
be  alike  in  every  discernible  character.  If  these 
are  planted  in  a  space  a  foot  square,  it  will  be 
found,  after  two  or  three  weeks,  that  some  indi- 
viduals are  outstripping  the  others,  although  all 
of  them  came  up  equally  well  and  were  at  first 
practically  indistinguishable.  This  means  that, 
because  of  a  little  advantage  in  food  or  moisture, 
or  other  circumstance,  some  plants  have  obtained 
the  mastery  and  are  crowding  out  the  less  fortu- 
nate ones.  Here  is  a  variation  taking  place  before 
our  very  eyes,  and  we  may  be  able  to  see  the  exact 


16      FACT   AND   PHILOSOPHY   OF   VARIATION. 

cause  of  it.  Moreover,  variations  which  originate 
in  this  way  may  pass  down  to  the  offspring 
through  the  seeds,  as  in  the  case  of  "  viney  "  peas, 
which  are  grown  on  too  rich  soil.  All  this  is  a 
matter  of  the  commonest  observation  with  the 
gardener,  who  is  so  accustomed  to  seeing  great 
differences  arise  in  batches  of  plants,  all  of  which 
start  equal  and  with  an  equal  chance,  that  he 
never  thinks  to  comment  upon  the  occurrence. 
In  fact,  the  theory  and  practice  of  agriculture 
rest  upon  the  fact  that  plants  can  be  modified 
greatly  by  the  conditions  in  which  they  grow, 
after  they  have  become  thoroughly  established  in 
the  soil.  Plants  may  start  equal,  but  may  differ 
widely  at  the  harvest ;  and  this  difference  may  be 
controlled  to  a  nicety  by  the  cultivator.  Every 
farmer  knows,  too,  that  the  best  results  for  the 
succeeding  year  are  to  be  got  only  when  he  selects 
seeds  from  the  best  which  he  has  been  able  to  pro- 
duce this  year.  So,  given  uniformity  or  equality 
at  the  start,  the  operator  moulds  the  individual 
plants  largely  at  his  will. 

Having  noticed  that  physical  environments  may 
modify  plants,  we  are  now  ready  to  consider  just 
what  changes  in  these  circumstances  of  plant  life 
are  most  fruitful  in  the  production  of  new  forms. 

1.  Variation  in  Food  Supply.  —  The  greater 
part  of  the  changes  in  the  physical  conditions 
of   life   hinge  upon   the  relative  supply  of    food. 


FOOD   SUPPLY   AND    VARIATION.  17 

Climbing  plants  assume  their  form  because,  by 
virtue  of  tlie  divergence  of  character,  they  are 
enabled  to  lit  themselves  into  places  which  other 
plants  cannot  occupy.  They  rear  their  foliage 
into  the  air,  where  food  and  sunlight  are  unappro- 
priated. The  lower  branches  of  the  tree-top  die, 
and  the  others  thereby  appropriate  the  more  food 
and  grow  the  faster.  The  entire  practice  of  agri- 
culture is  built  upon  the  augmentation  of  the 
food  supply.  For  this  purpose,  we  set  the  plants 
in  isolated  positions,  we  till  the  ground,  keep 
down  other  plants  or  weeds,  add  plant  food  to 
the  soil,  and  prune  the  tree  and  thin  the  fruit. 

Thomas  Andrew  Knight,  the  chief  of  horticul- 
tural philosophers,  appears  to  have  been  the  first 
to  clearly  enunciate  the  law  that  excess  of  food 
supply  is  the  most  prolific  cause  of  the  variation 
of  plants.  Darwin  subscribes  to  it  without  re- 
serve :  "Of  all  the  causes  which  induce  varia- 
bility, excess  of  food,  whether  or  not  changed  in 
nature,  is  probably  the  most  powerful."  Alex- 
ander Braun,  an  earlier  writer  upon  the  philosophy 
of  the  organic  world,  said  that  "  it  appears  rather, 
on  the  whole,  as  if  the  unusual  conditions  favor- 
able to  a  luxuriant  state  of  development,  afforded 
by  cultivation,  awakened  in  the  plant  the  inward 
impulse  to  the  display  of  all  those  variations  pos- 
sible within  the  more  or  less  narrowly  circum- 
scribed limits   of   the   species."      It  is    generally 


18      FACT    AND    PHILOSOPHY    OF    VARIATION. 

agreed  by  those  who  have  given  the  matter  much 
thought,  that  an  excess  of  food  above  the  amount 
normally  or  habitually  received  is  one  .of  the  very 
chief,  if  not  the  most  dominant,  causes  of  indi- 
vidual differences  in  plants.  Certainly  every 
farmer  and  gardener  knows  that  the  richer  the 
soil  in  available  plant  food,  the  stronger  and  the 
more  abnormal  and  unusual  his  product  will  be. 

If,  then,  excess  of  food  supply  is  a  strong  factor 
in  the  modification  of  plants,  and  if  the  one  fun- 
damental aim  of  agriculture  is  to  supply  food  in 
excess  of  natural  conditions,  it  must  naturally 
follow  that  cultivated  plants  should  be  of  all 
others  the  most  variable.  This  is  notably  true. 
Now,  the  first  variation  which  usually  comes  of 
this  liberal  food  supply  is  increase  in  mere  big- 
ness. Probably  every  plant  which  has  ever  been 
cultivated  has  increased  its  stature  or  the  size  of 
some  or  all  of  its  parts.  Moreover,  this  is  gener- 
ally the  direct  object  of  cultivation,  —  to  secure 
larger  herbage,  fruits,  seeds,  or  flowers.  Inci- 
dentally, we  find  here  an  indubitable  proof  of  the 
truth  of  the  hypothesis  of  evolution,  for  if  it  were 
impossible  for  plants  to  vary  or  to  assume  new 
characters,  there  would  be  no  cultivation  and  no 
agriculture;  for  there  would  be  little  object  in 
cultivating  a  product  if  it  grew  equally  well  in 
the  wild. 

This  variation  into  mere  bigness  is  more  impor- 


BREAKING   THE   TYPE.  19 

tant  than  it  may  seem  at  first  sight.  All  thought- 
ful horticulturists  agree  in  believing  that  the  first 
thing  to  be- done  in  ameliorating  any  plant  is  to 
4 'break  the  type,"  that  is,  to  cause  it  to  vary. 
The  particular  direction  of  variation  is  not  so 
important,  at  first;  for  all  experience  has  shown 
that  if  once  the  seedlings  of  a  plant  begin  to 
depart  from  the  parental  type,  other  and  various 
modifications  will  soon  follow.  If  a  plant  is  once 
strongly  modified  in  size,  variations  in  shape, 
color,  flavor,  or  other  attributes  are  forthcoming. 
This  apparent  accumulation  of  variation  seems  at 
first  to  be  incapable  of  scientific  explanation,  but 
the  reasons  for  it  are  not  difficult  to  understand 
when  once  they  are  presented. 

When  plants  are  placed  in  new  conditions, 
whether  in  the  wild  or  in  cultivation,  then  they 
begin  to  vary,  but  usually  only  in  one  direction 
at  first,  although  the  amount  of  the  variation,  and 
sometimes  the  kind,  is  determined  very  largely 
by  the  nature  and  the  extent  of  the  change  in  the 
conditions.  This  initial  variation,  particularly 
when  plants  are  transferred  to  cultivated  areas, 
is  generally  in  the  direction  of  greater  size  con- 
sequent upon  the  greater  amount  of  food.  This 
initial  variation  is  generally  soon  followed  by 
others  in  various  directions,  and  from  these  the 
cultivator  may  be  able  to  establish  new  varieties. 
We  now  ask  ourselves  why  these  many  variations 


20      FACT   AND    PHILOSOPHY    OF    VARIATION. 

appear  when  once  the  type  begins  to  modify  itself. 
Consider  the  fact  that  the  world  is  now  full  of 
plants.  In  untamed  nature,  not  one  more  plant 
can  grow  unless  another  plant  dies.  All  plants, 
therefore,  are  held  down  to  narrow  limits  of  num- 
bers, and  since  there  are  so  few  individuals, — 
in  comparison  with  the  seeds  and  buds  which 
each  plant  produces  for  the  chance  of  multiplying 
itself,  —  there  must  be,  also,  few  kinds  and  degrees 
of  individual  differences.  The  farther  and  more 
freely  a  plant  distributes  itself,  the  greater  must 
be  the  differences  between  the  various  individuals, 
because  they  must  adapt  themselves  to  a  wider 
range  of  conditions.  All  plants  are  held  in  equi- 
librium, so  to  speak;  but  the  plant  organism  is 
plastic  by  nature  and  quickly  responds  to  every 
touch  of  environment;  so,  as  soon  as  the  pressure 
is  removed  in  any  direction,  the  plant  at  once 
springs  into  the  breach.  Recall  the  monotonous 
vegetation  of  the  deep  forest,  where  the  battle 
of  centuries  has  subdued  all  but  the  strongest. 
Clear  away  the  forest,  and  then  observe  the 
tierce  scramble  for  place  and  life  amongst  a  multi- 
tude of  forms  which  spring  in  for  an  opportunity 
to  better  their  conditions.  In  a  few  years  more, 
the  tender  low  herbs  have  gone.  The  briars  and 
underbrush  have  usurped  the  land.  As  time  goes 
on,  one  species  after  another  perishes,  and  when 
the  place  is  again  reforested,  two  or  three  species 


EQUILIBRIUM   IN   NATURE.  21 

hold  undisputed  sway  over  the  land.  The  pop- 
lars which  followed  the  pines  have  long  since  per- 
ished and  pines  again  dominate  the  forest.  Or, 
if  the  area  were  turned  to  pasture  a  few  years 
after  the  woods  were  removed,  the  herbs  and 
bushes  die  with  the  browsing,  and  in  time  the 
June  grass  covers  the  whole  landscape  with  the 
mantle  of  conquest.  So  plants  may  be  said  to 
be  always  ready  to  fill  new  places  in  the  polity 
of  nature  by  adapting  themselves  to  the  new  cir- 
cumstances as  they  grow  into  them.  The  appear- 
ing of  any  one  marked  variation,  therefore,  is 
evidence  that  the  plant  has  found  a  new  condi- 
tion, that  the  pressure  is  somewhat  lifted,  and 
that  its  whole  plastic  organization  will  soon  re- 
spond to  the  new  environment.  It  is  apparent, 
then,  how  the  simplest  and  rudest  cultivation  has 
been  able,  through  the  centuries,  to  so  profoundly 
modify  our  domestic  plants  that  we  are  often 
unable  to  recognize  the  forms  from  which  they 
sprung. 

We  must  not  forget  to  notice,  at  this  point, 
that  the  food  supply  differs  amongst  the  various 
branches  of  the  same  plant.  Some  branches,  by 
reason  of  position  with  reference  to  the  main 
trunk  or  with  reference  to  air  and  sunlight,  or, 
because  of  a  better  start  in  the  beginning  as  a 
result  of  some  incidental  advantage,  gain  the 
mastery  over   others  and  crowd  them  out.     We 


22      FACT    AND    PHILOSOPHY    OF    VARIATION. 

have  already  seen  that  no  two  branches  on  a  plant 
are  alike  ;  and  we  are  now  able  to  understand  that 
sports  or  bud-varieties  are  no  more  inexplicable 
than  seed- varieties  are. 

Cultivation  is  really  but  an  extension  or  intensi- 
fication of  nature's  methods  of  dealing  with  the 
plant  world.  The  ultimate  object  of  both  nature 
and  man  is  to  supply  more  food.  The  variations 
which  arise  from  the  effects  of  mere  cultivation, 
therefore,  are  in  kind  very  like  those  which  nature 
produces,  the  chief  difference  being  that  of  degree. 
The  accustomed  operations  of  the  farmer,  there- 
fore, have  been  powerful  agents  in  the  evolution 
of  vegetable  forms.  The  ways  in  which  cultiva- 
tion affords  a  more  liberal  food  supply  are  as  fol- 
lows :  — 

1.  By  isolating  the  individual  plant.  The 
husbandman  sets  each  plant  by  itself,  and  then 
protects  it  by  destroying  the  weeds  or  plants 
which  endeavor  to  crowd  it  out.  There  is  a 
partial  exception  to  this  in  the  "sowed  crops," 
like  the  grains,  and  it  is  noticeable  that  variation 
in  these  plants  is  usually  less  marked  than  in  the 
"hoed  crops." 

2.  By  giving  the  plant  the  advantage  of  posi- 
tion, whereby  it  is  allowed  the  most  congenial 
exposure  to  sun  and  contour  of  land. 

3.  By  increasing  the  fertility  of  the  soil,  either 
by    tillage    or    the    direct    application    of    plant 


MEANS    OF    AUGMENTING   FOOD    SUPPLY.       23 

food,  or  both.  Rich  and  moist  soils  tend  to 
"  break "  the  type,  —  or  to  cause  initial  varia- 
tions, —  to  produce  verdant  colors  and  loss  of 
saccharine  and  pungent  qualities,  to  induce  re- 
dundant growth,  and  to  delay  maturity  and 
thereby  to  render  plants  tender  to  cold  winter 
climates. 

4.  By  thinning  the  tops  of  plants  and  the 
fruits,  whereby  the  remaining  parts  receive  an 
amount  of  food  in  excess  of  the  habitual  allow- 
ance. 

5.  By  divergence  of  character  in  associated 
plants.  It  is  well  known  that  a  field  which  is 
planted  so  thickly  to  corn  that  it  cannot  grow 
more  with  profit,  may  still  grow  pumpkins  be- 
tween. The  pumpkins  and  the  corn  are  so  unlike 
in  form  that  they  complement  each  other,  the  one 
filling  the  niche  which  the  other  is  not  fitted  to 
occupy.  We  have  already  seen  that  a  copse  ever 
so  full  of  bushes  may  still  grow  vines.  A  meadow 
which  is  full  of  timothy  may  still  grow  clover 
in  the  bottom,  and  land  which  is  covered  with 
apple  trees  still  grows  weeds  beneath.  "  The 
more  diversified  the  descendants  from  any  one 
species  become  in  structure,  constitution,  and 
habits/'  writes  Darwin,  "by  so  much  will  they 
be  better  enabled  to  seize  on  many  and  widely 
diversified  places  in  the  polity  of  nature,  and  so 
be  enabled  to  increase  in  numbers." 


24      FACT   AND   PHILOSOPHY   OF    VARIATION". 

2.  Variation  in  Climate. — The  fact  that  any 
distinct  climatic  region  usually  has  plants  which 
are  very  closely  related  to  those  of  other  climatic 
regions  in  the  same  zone,  points  strongly  to  the 
probable  profound  modification  of  plants  by  cli- 
mate. And,  furthermore,  we  should  expect  that  if 
the  food  environment  modifies  plants,  the  climatic 
environment  must  have  the  same  power.  More- 
over, there  is  abundant  historical  and  experimental 
proof  that  climate  is  capable  of  greatly  modifying 
the  vegetable  kingdom.  There  are  those  who 
contradict  any  great  effect  of  climate  in  the  varia- 
tion of  plants,  and  acclimatization  has  been  even 
stoutly  denied.  These  persons  make  the  mistake 
of  asking  that  a  visible  modification  take  place  at 
once  upon  the  transfer  of  a  plant  from  one  climate 
to  another,  and  they  also  err  in  supposing  that  a 
plant  can  adapt  itself  to  a  cold  climate  only  by 
developing  a  capability  to  withstand  more  cold. 
Indian  corn  is  sometimes  cited  as  proof  that 
plants  do  not  become  acclimatized,  for  it  is  as 
tender  to  frost  now  as  ever,  for  all  that  we  know. 
Yet  this  very  plant  affords  a  most  unequivocal 
example  of  complete  acclimatization,  because  it 
has  shortened  its  period  of  growth  fully  one-half 
to  enable  it  to  escape  the  cold  of  the  north. 

The  influence  of  a  change  of  climate  upon 
plants,  or,  what  may  amount  to  the  same  thing, 
the  result  of  a  transfer  of  plants  to  new  climates, 


fggmrr  muvr 


CLIMATE    AND    VARIATION.  25 

is  so  complex  and  so  general  that  no  detailed  dis- 
cussion of  the  subject  can  be  made  at  this  time. 
It  will  answer  our  present  purpose  to  briefly 
designate  the  ways  in  which  climate  modifies 
plants :  — 

1.  Climate  greatly  modifies  the  stature  of  plants. 
They  become  dwarfer  in  high  latitudes  and  alti- 
tudes. 

2.  It  modifies  form.  Plants  tend  to  be  broader- 
headed,  and  also  more  prostrate,  in  high  latitudes 
and  altitudes. 

3.  Proportionate  leanness  generally  increases, 
at  the  same  time. 

4.  There  is,  also,  often  a  gain  in  comparative 
fruitfulness  following  transfer  towards  the  poles. 

5.  The  colors  of  leaves,  flowers,  fruits,  and 
seeds  are  greatly  influenced  by  climate,  there 
being  a  general  tendency,  in  plants  of  temperate 
regions,  to  augmentation  in  intensity  of  colors  as 
they  are  carried  towards  the  poles. 

6.  There  is  modification  in  the  flavor  and  es- 
sential ingredients  of  various  parts,  following  a 
change  of  climate. 

7.  There  is  a  variation  in  variability  itself.  The 
more  difficult  the  climate  in  which  a  plant  finds 
itself,  the  more  it  tends  to  vary  to  meet  the  uncon- 
genial environments.  In  the  high  north,  many 
plants  are  so  variable  that  the  marks  used  to  iden- 
tify the  species  in  other  latitudes  are  often  lost. 


26      FACT   AND   PHILOSOPHY    OF    VARIATION. 

8.  There  may  be  a  profound  variation  or  modi- 
fication in  constitution  and  habit  by  which  plants 
become  acclimatized,  or  enabled  to  endure  a  cli- 
mate at  first  injurious  to  them.  This  may  occur 
by  a  variation  in  the  constitution  of  the  descend- 
ants, which  enables  them  to  endure  directly  more 
untoward  conditions.  It  generally  comes  about, 
however,  through  a  change  in  habit,  by  which 
plants,  when  transferred  towards  the  poles,  shorten 
their  season  of  growth  or  even  become  annuals. 
Plants  become  more  sensitive  to  spring  tempera- 
tures in  cold  climates,  so  that  they  start  relatively 
much  earlier  in  the  season  —  that  is,  at  a  lower 
sum-temperature  —  than  they  do  in  warm  climates. 
Any  one  who  has  passed  the  springtime  in  both 
the  North  and  South  must  have  noticed  how  much 
more  suddenly  the  vegetation  comes  forward  in 
the  North;  and  it  is  surprising  how  the  spring- 
sowed  crops  accelerate  their  growth  in  the  North 
over  those  in  the  South. 

The  characters  which  result  from  a  change  of 
climatic  environment  are  peculiarly  within  the 
control  of  the  agriculturist,  for  a  leading  factor 
in  his  business  is  the  transfer  of  plants  far  and 
wide  over  the  earth.  So  it  has  come  that  the 
staple  varieties  of  the  important  grains  and  fruits 
are  unlike  in  Europe  and  America  and  in  all  great 
geographical  areas,  although  all  the  various  forms 
may  have  sprung  from  one  ancestor  within  historic 


CLIMATE    AND    VARIATION.  27 

times.  A  new  country  is  stocked  with  varieties 
from  the  mother  country ;  hut  in  the  course  of 
a  few  generations  it  is  found  that  the  varieties 
in  cultivation  are  unlike  the  ones  originally  in- 
troduced, and  from  which  they  came.  As  wild 
plants  have  become  separated  from  each  other  as 
species  in  the  different  geographical  regions,  so 
the  cultivated  plants  soon  begin  to  follow  similar 
lines  of  divergence.  In  the  beginning  of  the  colo- 
nization of  this  country,  for  example,  all  the  vari- 
eties of  apples  were  of  European  origin.  But  in 
1817,  over  sixty  per  cent  of  the  apples  recommended 
for  cultivation  here  were  of  American  origin,  that 
is,  American-groAvn  seedlings  from  the  original 
stock.  At  the  present  time,  fully  ninety  per  cent 
of  the  popular  apples  of  the  Atlantic  states  are 
American  productions.  The  northern  states  of 
the  Mississippi  valley,  to  which  most  of  our  east- 
ern apples  are  not  adapted,  are  now  witness- 
ing a  similar  transformation  in  the  adaptation 
and  modification  of  the  varieties  introduced 
from  the  East  and  from  Russia.  The  newly 
introduced  Japanese  plums  are  conceded  to  be 
great  acquisitions  to  our  fruit-growing,  but  no 
doubt  the  best  results  are  yet  to  come  with  the 
origination  of  domestic  varieties  of  them.  So 
there  is  an  irresistible  tendency  towards  a  di- 
vergence of  forms  in  different  continental  or 
geographical    regions,    and    much    of    the    inevi- 


28      FACT    AND    PHILOSOPHY   OF    VARIATION. 

table  result  is  no  doubt  chargeable  to  climatic 
environment. 

3.  Change  of  seed.  Bud-variation.  —  I  will 
pause  for  a  moment  to  consider  two  agencies  or 
phenomena  which  are  often  associated  with  the 
genesis  of  varieties.  One  of  these  is  the  fact 
that  the  simple  change  of  seed  from  one  locality 
to  another  generally  gives  a  larger  or  better 
product  or  even  more  marked  variation.  Mere 
transfer  of  seed  is  not  of  itself,  however,  a  cause 
of  variation.  The  change  is  beneficial  because 
it  fits  together  characters  and  environments  which 
are  not  in  equilibrium  with  each  other.  A  plant 
which  is  grown  for  several  years  in  one  set  of  con- 
ditions becomes  fitted  into  them,  so  to  speak,  and 
is  in  a  comparative  state  of  rest.  When  the  plant 
or  its  progeny  is  taken  to  other  conditions,  all  the 
adjustments  are  broken  up,  and  in  the  refitting  to 
the  new  circumstances  new  or  strange  characters 
are  apt  to  appear.  We  shall  leave  this  subject 
for  the  present,  expecting  to  give  it  a  fuller 
treatment  in  the  second  lecture. 

Bud-variation,  or  sport,  is  a  name  given  to 
those  branches  which  are  so  much  unlike  the 
normal  plant  in  any  particular  that  they  attract 
attention.  Many  garden  varieties  are  simply 
multiplications  of  such  abnormal  branches.  This 
bud-variation  is  commonly  held  to  be  such  an 
unusual   and    inexplicable  phenomenon  that  it  is 


STRUGGLE    FOR    LIFE    AND    VARIATION.        29 

considered  apart  from  all  the  general  discussions 
of  variation.  It  is  not,  of  course,  a  cause  of  vari- 
ability, but  simply  an  effect  of  some  antecedent, 
the  same  as  seed-variation  is.  We  have  already 
seen  that  all  the  different  branches,  or  even  joints, 
of  any  plant  are,  in  a  very  important  sense,  dis- 
tinct individuals,  since  every  one  develops  its 
own  organs,  each  is  capable  of  reproducing  itself 
independently,  and  each  is  unlike  every  other 
because  it  is  acted  upon  differently  by  environ- 
ment and  food  supply.  It  is  not  strange,  there- 
fore, that  some  of  these  individuals  should  now 
and  then  depart  very  widely  from  the  ordinary 
type,  and  thereby  attract  the  attention  of  a  gar- 
dener, who  would  forthwith  make  cuttings  or  set 
grafts  from  the  part.  Every  branch  is  a  bud- 
variety,  just  as  truly  as  every  seedling  is  a  seed- 
variety, —  since  no  seedling  is  ever  exactly  like  its 
parent,  —  and  there  should  be  no  greater  mystery 
connected  with  the  sports  of  buds  than  there  is 
with  the  variations  from  seeds,  for  the  causes 
which  produce  the  one  may  be  and  are  equally 
competent  to  produce  the  other. 

d.    Straggle  for  Life  a  Cause  of  Variation. 

We  have  seen  that  the  world  is  full  of  plants. 
There  is  room  for  more  only  as  the  present  indi- 
viduals  die.      Yet   nearly  every  species  produces 


BO      FACT    AND    PHILOSOPHY   OF    VARIATION. 

a  great  number  of  seeds,  and  makes  a  most  stren- 
uous effort  to  multiply  its  kind.  Any  one  plant, 
if  left  to  itself,  is  capable  of  covering  the  earth  in 
a  comparatively  short  time.  A  fierce  struggle  for 
a  chance  to  live  is  therefore  inevitable.  This  con- 
flict is  most  apparent  to  the  general  observer  in 
the  springtime,  when  every  "herb  yielding  seed 
after  his  kind,  and  the  tree  yielding  fruit,  whose 
seed  was  in  itself,  after  his  kind,"  are  sending 
forth  a  host  of  sturdy  offspring.  The  very  land 
seems  to  be  pregnant  with  weeds  and  aspiring 
young  growths.  But  by  midsummer  the  num- 
bers may  be  less.  The  weaker  and  less  fortunate 
ones  have  perished,  and  the  victors  have  waxed 
stronger  thereby.  The  annual  and  half  of  the 
biennial  species  complete  their  course  upon  the 
approach  of  winter,  and  the  older  perennial  herbs 
are  becoming  weak;  so  in  the  succeeding  spring- 
time there  is  again  a  fierce  combat  for  the  vacant 
places. 

One  of  the  results  of  this  conflict  is  the  adjust- 
ment of  plants  to  each  other.  We  have  seen  how 
the  climbing  plant  insinuates  itself  in  amongst  the 
shrubberies  and  ties  them  together  in  an  impene- 
trable tangle  in  order  that  it,  itself,  may  have  a 
chance  to  live.  So  the  low  plants  of  the  deep 
forest  are  such  as  have  been  plastic  enough  to 
adapt  themselves  to  the  damp  shades.  Thus 
plants  have  developed   companionships  or   diver- 


FIXATION   OF   VARIATIONS.  31 

gences  in  characters,  by  means  of  which,  under 
the  stress  of  circumstances,  they  are  able  to  live 
together.  Plants  have  adapted  themselves  to 
other  plants  as  truly  as  they  have  adapted  them- 
selves to  soil  or  climate ;  and  if  these  latter  en- 
vironments are  ever  the  sources  or  causes  of 
variation,  then  the  first  must  be  also.  I  must 
look  upon  the  struggle  for  existence,  therefore, 
as  itself  a  cause  of  individual  differences,  since 
we  know  that  any  continued  pressure  from  with- 
out awakens  an  adaptive  response  in  the  form  of 
the  vegetable  organism. 

III.   The   Choice   and   Fixation    of  Varia- 
tions. 

We  have  now  seen  that  every  living  object  is 
unlike  every  other.  In  plants,  even  every  branch 
is  unlike  any  other  branch.  We  have  endeav- 
ored to  discover  some  of  the  causes  of  these  uni- 
versal differences.  We  have  found  that  they 
are  intimately  associated  with  the  welfare  of  the 
type  or  species,  inasmuch  as  they  appear,  for 
the  most  part,  to  be  the  means  of  fitting  the 
plant  to  live  in  the  conditions  in  which  it  is 
placed.  But  we  have  also  seen  that  there  are 
more  individuals  than  can  find  a  place  to  live. 
How,  then,  does  nature  choose  the  best  from  the 
poorest,  and,  having  chosen  them,  how  does  she 


32      FACT   AND    PHILOSOPHY    OF    VARIATION. 

endeavor  to  fix  them,  or  to  make  them  more  or 
less  stable  ? 

"  This  preservation  of  favorable  individual  dif- 
ferences and  variations,  and  the  destruction  of 
those  which  are  injurious,  I  have  called  Natural 
Selection  or  the  Survival  of  the  Fittest."  This 
is  the  philosophy  which  was  propounded  by  Dar- 
win, and  which  will  carry  his  name  to  the  last 
generation  of  men.  It  looks  simple  enough. 
Those  forms  which  are  best  fitted  to  live,  do  live, 
because  they  crowd  out  the  others.  Yet,  this 
simple  principle  of  natural  selection  was  the  first 
explanation  of  the  process  of  evolution  which 
seemed  to  be  capable  of  interpreting  the  complex 
phenomena  of  the  forms  of  organic  life.  For  a 
time,  this  philosophy  was  thought  to  be  the  one 
fundamental  motive  of  the  evolution  or  progres- 
sion of  life,  but  we  are  now  convinced  that  there 
are  other  motives  or  forces  at  work  ;  but  it  seems 
to  be  indisputable  that  natural  selection  is  the 
chief  force  underlying  the  evolution  of  plants, 
and  it  is  the  only  one  with  which  the  person  who 
desires  to  breed  plants  need  intimately  concern 
himself. 

We  must  now  determine  what  a  variety  is.  This 
is  a  vexed  question,  and  one  Avhich  seems  never  to 
be  capable  of  an  answer  which  is  satisfactory  to 
the  gardener.  Time  and  again,  some  person  has 
introduced  what  lie  considered  to  be  a  distinct  new 


WHAT    IS    A    VARIETY?  33 

variety,  only  to  find  that  other  horticulturists  dis- 
pute him  and  declare  that  it  is  only  some  old  vari- 
ety renamed.  And  yet  the  introducer  knows  that 
he  has  not  renamed  an  old  variety,  but  that  he  has 
simply  propagated  a  form  which  appeared  or  origi- 
nated upon  his  own  grounds. 

Now,  let  us  see.  Nature  starts  out  with  the 
individual  to  make  a  new  form.  Every  individual 
is  unlike  eveiy  other  one.  When  the  individual 
differences  are  so  well  marked  that  Ave  can  readily 
describe  and  distinguish  them,  and  so  permanent 
that  they  pass  down  nearly  intact  to  a  few  genera- 
tions, we  say  that  we  have  a  variety.  If  the  differ- 
ences are  still  more  marked,  we  say  that  we  have  a 
species.  Where  the  variety  ends  and  the  species 
begins  it  may  be  utterly  impossible  to  determine  ; 
so  we  mark  off  at  a  certain  point  and  say,  arbi- 
trarily, that  this  much  is  variety  and  that  much 
is  species.  Asa  Gray  once  said  to  me  that  "  species 
are  judgments."  Now,  if  there  is  no  hard  and 
fast  line  between  the  variety  and  the  species,  so 
there  is  none  between  the  individual  and  the  vari- 
ety ;  for  a  variety  is  only  the  family  of  descendants 
from  some  one  individual.  That  is,  the  idea  of 
variety  or  species  rests  upon  difference,  but  just 
how  much  difference  shall  constitute  one  grade  or 
another  is  a  matter  of  individual  opinion.  So, 
when  two  gardeners  cannot  agree  as  to  whether  a 
given  introduction  is  a  new  variety  or  not,  they 


34      FACT    AND    PHILOSOPHY    OF    VARIATION. 

are  having  just  the  same  difficulty  that  two  botan- 
ists have  when  they  cannot  decide  whether  two 
plants  are  two  species  or  one. 

It  is  apparent,  then,  that  every  individual  plant 
is  a  distinct  variety,  only  that  the  differences  be- 
tween it  and  other  individuals  may  be  so  slight 
that  they  have  no  practical  utility  and  cannot  be 
described  and  recorded.  Just  as  soon  as  an  indi- 
vidual plant  has  characters  so  unlike  its  kin  that 
it  has  some  commercial  value,  then  the  plant  will 
be  increased  by  cuttings  or  grafts  or  seeds,  the 
brood  of  offspring  will  be  given  a  name,  and  a  new 
variety  is  born. 

Individuals  with  the  same  general  features  may 
appear  simultaneously  in  two  or  more  places,  and 
two  or  more  men  may  propagate,  name,  and  intro- 
duce them.  When  they  are  all  brought  together 
and  compared,  it  will  be  said  that  they  are  all  the 
same  variety,  that,  according  to  the  rules  of  nomen- 
clature, the  brood  which  chanced  to  be  named  first 
must  "  stand  "  or  be  held  to  be  the  type  of  the 
variety,  and  that  the  other  names  must  become 
synonyms.  Yet  some  person  may  discover  minor 
differences  in  them  and  demand  that  the  varieties 
be  kept  distinct.  So  the  see-saw  goes  on  —  a  vari- 
ety is  a  variety  so  long  as  it  answers  some  purpose 
in  use  or  trade,  and  it  is  not  a  variety  when  it  is  so 
much  like  some  other  variety  that  it  has  no  merit 
which  the  other  does  not  possess. 


WHAT   IS    A    VARIETY  ?  35 

As  soon  as  a  plant  appears  with  some  feature 
which  is  more  desirable  than  anything  which  has 
preceded  it,  therefore,  it  may  be  made  the  begin- 
ning of  a  new  variety.  Man  chooses  it,  and  then 
propagates  it.  This  is  human  selection.  If  nat- 
ure did  the  same,  it  would  be  natural  selection. 

Now,  how  does  nature  preserve  or  fix  this  type  ? 
She  does  not  preserve  it !  She  simply  chooses  it 
as  a  beginning  and  gradually  modifies  it  and  shapes 
it  into  the  form  which  she  needs.  She  has  no  per- 
manent forms.  There  is  a  general  onward  pro- 
gression of  every  type  either  towards  other  types 
or  towards  extinction.  We  have  seen  that  nature 
is  constantly  choosing  and  selecting.  If  she  selects 
an  individual  for  the  beginning  of  a  race,  then 
she  selects  just  as  keenly  from  every  offspring  of 
that  individual,  and  so  on  to  the  end  of  time.  The 
process  never  stops.  So  nature  fixes  her  forms  by 
keeping  them  moving,  growing,  constantly  develop- 
ing farther  away  from  their  beginnings. 

Now,  man  does  the  same  thing.  A  plant  in  a 
cabbage  row  pleases  him.  It  has  a  solid,  small 
head  and  stout  stem.  He  stores  it  away  for  seed. 
Amongst  the  offspring,  perhaps  fifty  per  cent  are 
as  good  as  the  parent.  These  are  saved.  So  the 
process  goes  on,  from  season  to  season.  In  four 
or  five  generations  of  plants,  he  finds  that  ninety 
per  cent  of  the  seeds  "come  true."  Then  he 
names  it  and  introduces  it.     It  is  well  advertised 


36      FACT    AND    PHILOSOPHY    OP    VARIATION. 

in  the  seed  catalogues.  Many  people  buy  the 
seeds.  Some  of  these  persons  will  grow  their 
own  seed,  and  every  one  of  them  has  a  different 
ideal  in  mind  when  selecting  the  seed  parents. 
So,  in  the  course  of  a  few  years,  it  is  found  that 
there  arc  really  several  more  or  less  different 
forms  going  under  the  same  name.  Some  person 
may  observe  this  difference  and  legitimately  in- 
troduce one  or  more  of  the  forms  as  distinct 
varieties.  Some  other  person,  however,  who  has 
known  the  history  of  the  stock  and  who  is  not 
aware  that  varieties  pass  into  other  forms,  objects 
to  the  new  names  and  declares  that  the  introducer 
is  imposing  upon  the  public. 

This  is  the  history  of  ninety-nine  out  of  every 
hundred  varieties  which  are  habitually  propa- 
gated by  seeds,  like  the  kitchen-garden  vege- 
tables and  the  annual  flowers.  Some  peculiar 
individual,  appearing  we  know  not  why,  is  dis- 
covered, and  seeds  are  saved  and  selection  — 
perhaps  unconscious  selection  —  begins.  After 
a  time  the  variety  is  broken  up  into  several,  or 
else,  if  it  varies  only  slightly  into  divergent 
forms,  the  whole  body  or  generations  of  the 
variety  move  onward,  gradually  departing  from 
the  initial  type  until  it  is  no  longer  the  same, 
although  it  may  still  bear  the  same  name.  The 
life  of  seed-varieties,  in  their  pure  and  original 
form,  is  very  short.      Even  the  best  of  them  are 


THE    PASSING    OF    VARIETIES.  37 

usually  measured  by  one  or  two  decades.  They 
run  out  or  pass  out  by  variation,  into  other  forms. 
The  Trophy  tomato  is  not  the  Trophy  tomato 
which  was  introduced  over  twenty  years  ago, 
although  it  bears  the  old  name  and  is  a  direct 
descendant  of  the  first  stock. 

In  plants  multiplied  by  buds  —  that  is,  by  bud- 
ding, grafting,  cuttings,  tubers,  and  the  like  — 
there  is  less  variation  in  the  offspring  than  in 
those  propagated  by  seeds.  Yet  we  have  seen 
that  no  two  Baldwin  apple  trees  —  all  of  which 
are  but  divisions,  more  or  less  remote,  of  the  one 
original  tree  —  are  alike,  and  now  and  then  one 
branch  of  a  fruit  tree  may  "  sport,"  or  develop  a 
strange  bud-variety.  We  knoAV,  too,  that  the 
same  variety  of  fruit  tree  takes  on  different 
characters  in  different  geographical  regions,  so 
that  the  Greening  apple  is  no  longer  the  Green- 
ing of  Rhode  Island  in  the  West  and  South.  So, 
it  is  apparent  that  even  when  we  divide  a  plant 
into  many  parts  and  distribute  the  members  far 
and  wide,  and  when  there  is  no  occasion  for  con- 
cerning ourselves  with  fixing  the  type,  —  even 
here  there  is  variation.  In  some  cases,  particu- 
larly in  those  in  which  we  multiply  the  plant  by 
dividing  abnormally  developed  parts,  there  is  a 
tendency  to  scatter  or  to  vary  in  many  directions, 
and  also  a  tendency  to  run  out  by  degeneration. 
This  is  admirably  true  of  the  potato,  varieties  of 


38      FACT   AND   PHILOSOPHY   OF    VARIATION. 

which,  in  ten  years  or  less,  become  so  mixed  in 
their  characters,  through  rapid  variation  and  de- 
terioration, that  we  must  return  to  seedling  pro- 
ductions for  a  new  start. 

The  gist  of  all  this  is  the  fact  that  nature  does 
not  make  new  varieties  or  species  by  leaps  and 
bounds  or  sudden  starts,  but  that  she  gradually 
produces  the  new  out  of  the  old,  so  slowly  that 
were  a  man  to  live  a  thousand  years  he  might 
note  little  change  in  the  grosser  features  of  plants. 
She  employs  crossing,  the  changes  in  all  the  varied 
conditions  of  life,  and  whatever  other  forces  she 
may  possess,  to  give  small  differences  between 
individuals.  Then  the  slow  and  cumulative 
process  of  selection  carries  the  work  forward 
forever.  Man  must  follow  the  same  course,  in 
the  main.  He  is  only  rarely  the  direct  means  of 
originating  variations.  He  finds  them  amongst 
the  normal  plants  of  the  field  and  garden.  His 
skill  and  science  are  exercised  in  the  selection 
and  so-called  breeding  of  the  offspring,  not  in 
the  original  genesis  of  the  new  form.  It  is  only 
in  those  plants  which  he  multiplies  by  simple 
division  that  he  gains  much  direct  profit  by 
crossing  or  hybridizing.  It  is  the  slow  and  pa- 
tient care  and  selection,  day  by  day,  which  per- 
manently ameliorate  and  improve  the  vegetable 
world.  Nature  starts  the  work  ;  man  may  com- 
plete it. 


LECTURE   II. 

THE  PHILOSOPHY  OF  THE  CROSSING  OP  PLANTS 
CONSIDERED  IN  REFERENCE  TO  THEIR  IMPROVE- 
MENT  UNDER   CULTIVATION. 

I.   The  Struggle  for  Life. 

It  is  now  understood  that  the  specific  forms  or 
groups  of  plants  have  been  determined  largely  by 
the  survival  of  the  fittest  in  a  long  and  severe 
struggle  for  existence.     The  proof  that  this  strug- 
gle  everywhere    exists   becomes    evident   upon  a 
moment's  reflection.     We  know  that  all  organisms 
are  eminently  variable.     In  fact,  no  two  plants  or 
animals  in  the  world  are  exactly  alike.     We  also 
know  that  very  few  of  the  whole  number  of  seeds 
which  are  produced  in  any  area  ever  grow  into 
plants.     If   all   the  seeds  produced   by  the  elms 
upon  Boston  Common  in  any  fruitful  year  were  to 
grow  into  trees,  this  city  would  become  a  forest  as 
a  result.     If  all  the  seeds  of  the  rarest  orchid  in 
our  woods  were  to  grow,  in  a  few  generations  of 
plants  even  our  farms  would  be  overrun.     If  all 
the  rabbits  which  are  born  were  to  reach  old  age, 
and  all  their  offspring  were  to  do  the  same,  in  less 
than  ten  years  every  vestige  of  herbage  would  be 

39 


40  PHILOSOPHY    OF   CROSSING   PLANTS. 

swept  from  the  country,  and  our  farms  would 
become  barren.  There  is,  then,  a  wonderful  latent 
potency  in  these  species ;  but  the  same  may  be 
said  of  every  species  of  plant  and  animal,  even  of 
man  himself.  If  one  species  of  plant  would  over- 
run and  usurp  the  land  if  it  increased  to  the  full 
extent  of  its  possibilities,  what  would  be  the  result 
if  each  of  the  two  thousand  and  sixty-one  plants 
known  to  inhabit  Middlesex  County  were  to  do  the 
same  ?  And  then  fancy  the  result  if  each  of  the 
animals,  from  rabbits  and  mice  to  frogs  and  leeches, 
were  to  increase  without  check  !  The  plagues  of 
Egypt  would  be  insignificant  in  the  comparison  ! 

The  fact  is,  the  world  is  not  big  enough  to  hold 
the  possible  first  offspring  of  the  plants  and  ani- 
mals at  this  moment  living  upon  it.  Struggle  for 
existence,  then,  is  inevitable,  and  it  must  be  severe. 
It  follows  as  a  necessity  that  those  seeds  grow  or 
those  plants  live  which  are  best  fitted  to  grow  and 
live,  or  which  are  fortunate  enough  to  find  a  con- 
genial foothold.  It  would  appear,  at  first  thought, 
that  much  depends  upon  the  accident  of  falling 
into  a  congenial  place,  or  one  unoccupied  by  other 
plants  or  animals ;  but,  inasmuch  as  scores  of 
plants  are  contending  for  every  unoccupied  place, 
it  follows  that  everywhere  only  the  fittest  can 
germinate  or  grow.  In  the  great  majority  of  cases, 
plants  grow  in  a  certain  place  because  the}^  are 
better  fitted  to  grow  there,  to  hold  their  own,  than 


STRUGGLE   FOR   EXISTENCE.  41 

any  other  plants  are  ;  and  the  instances  are  rare  in 
which  a  plant  is  so  fortunate  as  to  find  an  un- 
occupied place.  We  are  apt  to  think  that  plants 
chance  to  grow  where  we  find  them,  but  the  chance 
is  determined  by  law,  and  therefore  is  not  chance. 

Much  of  the  capability  of  a  plant  to  persist 
under  all  this  struggle  depends,  therefore,  upon 
how  much  it  varies ;  for  the  more  it  varies  the 
more  likely  it  is  to  find  places  of  least  struggle. 
It  grows  under  various  conditions,  —  in  sun  and 
shade,  in  sand  and  clay,  by  the  sea-shore  or  upon 
the  hills,  in  the  humidity  of  the  forest  or  the 
aridity  of  the  plain.  In  some  directions  it  very 
likely  finds  less  struggle  than  in  others,  and  in 
these  directions  it  expands  itself,  multiplies,  and 
gradually  dies  out  in  other  directions.  So  it 
happens  that  it  tends  to  take  on  new  forms,  or  to 
undergo  an  evolution.  In  the  meantime,  all  the 
intermediate  forms,  which  are  at  best  only  indif- 
ferently adapted  to  their  conditions,  tend  to  dis- 
appear. In  other  words,  gaps  appear  which  we 
call  "  missing  links."  The  weak  links  break  and 
fall  away,  and  what  was  once  a  chain  becomes  a  se- 
ries of  rings.  So  the  "  missing  links  "  are  amongst 
the  best  proofs  of  evolution. 

The  question  now  arises  as  to  the  cause  of  these 
numerous  variations  in  animals  and  plants.  Why 
are  no  two  individuals  in  nature  exactly  alike? 
The  question  is   exceedingly  difficult   to    answer. 


42  PHILOSOPHY    OF    CROSSING   PLANTS. 

It  was  once  said  that  plants  vary  because  it  is 
their  nature  to  vary ;  that  variation  is  a  necessary 
function,  as  much  as  growth  or  fructification. 
This  really  removes  the  question  beyond  the  reach 
of  philosophy  ;  and  direct  observation  leads  us  to 
think  that  some  variation,  at  least,  is  due  to  ex- 
ternal circumstances.  (See  Lecture  I.)  We  are 
now  looking  for  the  cause  of  variation  as  a  part  of 
the  scheme  of  evolution ;  and  we  are  wondering  if 
the  varied  surroundings,  or,  as  Darwin  put  it,  the 
"  changed  conditions  of  life,"  may  not  actually 
induce  variability.  This  conclusion  would  seem 
to  follow  from  the  fact  of  the  severe  and  universal 
struggle  in  nature  whereby  plants  are  constantly 
forced  into  new  and  strange  conditions.  But  there 
is  undoubtedly  much  variation  which  has  sprung 
from  more  remote  causes,  one  of  which  it  is  my 
purpose  to  discuss  here. 

II.   The  Division  of  Labor. 

In  the  lowest  animals  and  plants  —  which  are 
simply  single  cells  —  the  species  multiplies  by 
means  of  simple  division  or  by  budding.  One  in- 
dividual, of  itself,  becomes  two,  and  the  two  are 
therefore  recasts  of  the  one.  But,  as  organisms 
multiplied  and  conditions  became  more  complex, 
that  is,  as  struggle  increased,  there  came  a  differen- 
tiation in  the  parts  of  the  individual,  so  that  one 


DIVISION    OF   LABOR.  43 

cell  or  one  cluster  of  cells  performed  one  labor 
and  other  cells  performed  other  labor;  and  this 
tendency  resulted  in  the  development  of  organs. 
Simple  division,  therefore,  could  no  longer  repro- 
duce the  whole  complex  individual ;  and,  as  all 
organs  are  necessary  to  the  existence  of  life,  the 
organism  may  die  if  it  is  divided.  Along  with 
this  specialization  came  the  differentiation  into 
sex  ;  and  sex  clearly  has  two  offices  :  to  hand  over, 
by  some  mysterious  process,  the  complex  organ- 
ization of  the  parent  to  the  offspring,  and  also  to 
unite  the  essential  characters  or  tendencies  of  two 
beings  into  one.  The  second  office  is  manifestly 
the  greater,  for,  as  it  unites  two  organizations  into 
one,  it  insures  that  the  offspring  is  somewhat  un- 
like either  parent,  and  is  therefore  better  fitted  to 
seize  upon  any  place  or  condition  new  to  its  kind. 
And  as  the  generations  increase,  the  tendency 
to  variation  in  the  offspring  must  be  constantly 
greater,  because  the  impressions  of  a  greater  num- 
ber of  ancestors  are  transmitted  to  it.  I  have  said 
that  this  office  of  sex  to  induce  variation  is  more 
important  than  the  mere  fact  of  reproduction  of  a 
complex  organization ;  for  it  must  be  borne  in 
mind  that  the  complexity  of  organization  is  itself 
a  variation  and  adaptation  made  necessary  by  the 
increasing  struggle  for  existence. 

If,  therefore,  the  philosophy  of  sex  is  to  promote 
variation  by  the  union  of  different  individuals,  it 


44  PHILOSOPHY   OF    CROSSING   PLANTS. 

must  follow  that  the  greatest  variation  must  come 
from  parents  considerably  unlike  each  other  in 
their  minor  characters.  Thus  it  comes  that  in- 
breeding tends  to  weaken  a  type,  and  cross-breeding 
tends  to  strengthen  it.  And  at  this  point  we  meet 
the  particular  subject  which  I  am  to  present  to 
you.  I  have  introduced  you  to  this  preliminary 
sketch  because  I  contend  that  we  can  understand 
crossing  only  as  we  make  it  a  part  of  the  general 
philosophy  of  nature.  There  are  the  vaguest 
notions  concerning  the  possibilities  of  crossing, 
some  of  which  I  hope  to  correct  by  presenting  the 
subject  in  its  relations  to  the  general  aspects  of 
the  vegetable  world. 

We  are  now  prepared  to  understand  that  crossing 
is  good  for  the  species,  because  it  constantly  revi- 
talizes offspring  with  the  strongest  traits  of  the 
parents,  and  ever  presents  new  combinations  which 
enable  the  individuals  to  stand  a  better  chance  of 
securing  a  place  in  the  polity  of  nature.  The  fur- 
ther discussions  of  the  subject  are  such  as  have  to 
do  with  the  extent  to  which  crossing  is  possible  and 
advisable,  and  the  general  results  of  the  operation. 

III.   The  Limits  of  Crossing. 

If  crossing  is  good  for  the  species,  which  philoso- 
phy and  direct  experiment  abundantly  show,  it  is 
necessary  at  once  to  find  out  to  what  extent  it  can 


LIMITS    OF   CROSSING.  45 

be  carried.  Does  the  good  increase  in  proportion 
as  the  cross  becomes  more  violent,  or  as  the  parents 
are  more  and  more  unlike  ?  Or  do  we  soon  find  a 
limit  beyond  which  it  is  not  profitable  or  even 
possible  to  go, — a  point  at  which  we  say  that  "  an 
inch  is  as  good  as  an  ell  "  ?  If  great  variability  is 
good  for  the  species  in  the  struggle  for  existence, 
and  if  crossing  induces  variability  because  of  the 
union  of  unlike  individuals,  it  would  seem  to  follow 
that  the  more  unlike  the  parents  are,  the  greater 
will  be  the  variation  in  offspring  and  the  more  the 
type  will  prosper ;  and,  carrying  this  thought  to 
its  logical  conclusion,  we  should  expect  to  find  that 
the  most  closely  related  plants  would  constantly 
tend  to  refuse  to  cross,  because  the  offspring  of 
them  would  be  little  variable  and  therefore  little 
adapted  to  the  struggle  for  existence  ;  while  the 
most  widely  separated  plants  would  constantly  tend 
to  cross  more  and  more,  because  their  offspring 
would  present  the  greatest  possible  degrees  of  dif- 
ferences. We  should  expect,  for  instance,  that  a 
Baldwin  apple  would  be  less  likely  to  cross  with  a 
Greening  than  it  is  to  cross  with  a  peach  or  a  gourd. 
And,  if  we  should  carry  our  thought  a  step  farther, 
we  should  at  once  see  that  this  crossing  between 
different  species  would  soon  fill  in  all  differences 
between  those  species,  and  that  definite  specific 
types  would  cease  to  exist.  This  would  be  pande- 
monium, and  crossing  would  be  the  cause  of  it ! 


46  PHILOSOPHY   OF    CllOSSING   PLANTS. 

Now,  essentially  this  reasoning  has  been  ad- 
vanced to  combat  the  evolution  of  plants  and 
animals  by  means  of  natural  selection  ;  and  this 
proposition  that  intermixing  must  constantly  tend 
to  obliterate  all  differences  between  plants  and  to 
prevent  the  establishment  of  well-marked  types, 
has  been  called  the  "  swamping  effects  of  inter- 
crossing." It  is  exceedingly  important  that  we 
consider  this  question,  for  it  really  lies  at  the 
foundation  of  the  improvement  of  cultivated  plants 
by  means  of  crossing,  as  well  as  the  persistence 
and  evolution  of  varieties  and  species  under  wholly 
natural  conditions. 

We  find,  however,  that  distinct  species,  as  a  rule, 
refuse  to  cross ;  and  the  first  question  which  natu- 
rally arises  is,  What  is  the  immediate  cause  of  the 
refusal  of  plants  to  cross  ?  How  does  this  refusal 
express  itself?  It  comes  about  in  many  ways. 
The  commonest  cause  is  the  positive  refusal  of 
a  plant  to  allow  its  ovules  to  be  impregnated  by 
the  pollen  of  another  plant.  The  pollen  will  not 
"  take."  For  instance,  if  we  apply  the  pollen  of  a 
Hubbard  squash  to  the  flower  of  the  common  field 
pumpkin,  there  will  simply  be  no  result,  —  the 
fruit  will  not  form.  The  same  is  true  of  the  pear 
and  the  apple,  the  oat  and  the  wheat,  and  most 
very  unlike  species.  Or  the  refusal  may  come  in 
the  sterility  of  the  cross  or  hybrid  :  the  pollen  may 
"  take  "  and  seeds  may  be  formed  and  the  seeds 


BARRIERS    TO    INTERCROSSING.  47 

may  grow,  but  the  plants  which  they  produce  may 
be  wholly  barren,  sometimes  even  refusing  to  pro- 
duce flowers  as  well  as  seeds,  as  in  the  instance  of 
some  hybrids  between  the  Wild  Goose  plum  and 
the  peach.  Sometimes  the  refusal  to  cross  is  due 
to  some  difference  in  the  time  of  blooming  or  some 
incompatibility  in  the  structure  of  the  flowers.  But 
it  is  enough  for  our  purpose  to  know  that  there  are 
certain  characters  in  widely  dissimilar  plants  which 
prevent  intercrossing,  and  that  these  characters  are 
just  as  positive  and  just  as  much  influenced  by 
change  of  environment  and  natural  selection  as  are 
size,  color,  productiveness,  and  other  characters. 

Here,  then,  is  the  sufficient  answer  to  the 
proposition  that  intercrossing  must  swamp  all 
natural  selection,  and  also  the  explanation  of  the 
varying  and  often  restricted  limits  within  which 
crossing  is  possible.  That  is,  the  checks  to  cross- 
ing have  been  developed  through  the  principle 
of  universal  variability  and  natural  selection,  as 
has  been  shown  by  Darwin  and  Wallace.  Plants 
vary  in  their  reproductive  organs  and  powers  just 
the  same  as  they  do  in  other  directions ;  and  when 
such  a  variation  is  useful  it  is  perpetuated,  and 
when  hurtful  it  is  lost.  Suppose  that  a  certain 
well-marked  individual  of  a  species  should  find  an 
unusually  good  place  in  nature,  and  it  should  mul- 
tiply rapidly.  Crosses  would  be  made  between 
its  own  offspring  and  perhaps  between  those  off- 


48  PHILOSOPHY   OF    CROSSING   PLANTS. 

spring  and  itself  in  succeeding  years ;  and  it  is 
fair  to  suppose  that  some  of  the  crosses  would  be 
particularly  well  adapted  to  the  conditions  in 
which  the  parent  grew,  and  these  would  constantly 
tend  to  perpetuate  themselves,  while  less  adaptive 
forms  would  constantly  tend  to  disappear.  Now, 
the  same  thing  would  take  place  if  this  individual 
or  its  adaptive  offspring  were  to  cross  with  the 
main  stock  of  the  parent  species ;  for  all  the  off- 
spring of  such  a  cross  which  are  intermediate  in 
character  and  therefore  less  adapted  to  the  new  con- 
ditions would  tend  to  disappear,  and  the  two  types 
would,  as  a  result,  become  more  and  more  fixed  and 
the  tendency  to  cross  would  constantly  decrease. 

The  refusal  to  cross,  therefore,  becomes  a  posi- 
tive character  of  separation,  and  the  "  missing 
links "  which  result  from  crossing  are  no  more 
or  no  less  inexplicable  than  the  "  missing  links  " 
due  to  simple  selection  ;  or,  to  put  the  case  more 
accurately,  natural  selection  weeds  out  the  ten- 
dency to  promiscuous  crossing,  when  it  is  hurtful, 
in  just  the  same  manner  that  it  weeds  out  any 
other  injurious  tendency.  It  makes  no  difference 
in  what  way  this  tendency  expresses  itself,  whether 
in  some  constitutional  refusal  to  cross,  —  if  such 
exists,  —  or  in  infertility  of  offspring,  or  in  differ- 
ent times  of  blooming:  all  equally  come  under  the 
power  of  natural  selection.  We  are  apt  to  look 
upon  infertility  as  the  absence  of  a  character,  a 


HYBRIDS    RARELY   USEFUL.  49 

sort  of  a  negative  feature  which  is  somehow  not 
the  legitimate  property  of  natural  selection ;  but 
such  is  not  the  case.  We  are  perhaps  led  the 
more  to  this  feeling  because  the  word  infertility 
is  itself  negative,  and  because  we  associate  full  pro- 
ductiveness with  the  positive  attributes  of  plants. 
But  loss  of  productiveness  is  surely  no  more  a  sub- 
ject of  wonder  than  loss  of  color  or  size,  if  there  is 
some  corresponding  gain  to  be  accomplished.  In 
fact,  we  see,  in  numerous  plants  which  propagate 
easily  by  means  of  runners  and  suckers,  a  very  low 
degree  of  productiveness,  that  is,  infertility. 

Now,  if  this  reasoning  is  sound,  it  leads  us  to 
conclusions  quite  the  reverse  of  those  held  by  the 
advocates  of  the  swamping  effects  of  intercrossing, 
and  these  conclusions  are  of  the  most  vital  impor- 
tance to  every  man  who  tills  the  soil.  The  logical 
result  is  simply  this  :  the  best  results  of  crossing 
are  obtained,  as  a  rule,  when  the  cross  is  made  be- 
tween different  individuals  of  the  same  variety, 
or  at  farthest,  between  different  individuals  of  the 
same  species.  In  other  words,  hybrids  —  or  crosses 
between  species  —  are  rarely  useful  in  nature,  and 
it  follows  that  the  more  unlike  the  species  the  less 
useful  will  be  the  hybrids.  This,  I  am  aware,  is 
counter  to  the  notions  of  most  horticulturists,  and, 
if  true,  must  entirely  overthrow  our  common  think- 
ing upon  this  subject.  But  I  think  that  I  shall  be 
able  to  show  that  observation  and  experiment  lead 


50  PHILOSOPHY    OF    CROSSING    PLANTS. 

to  the  same  conclusion  to  which   our  philosophy 
has  brought  us. 


IV.  Function  of  the  Cross. 

a.    The    Gradual  Amelioration  of  the   Type. 

At  this  point  we  must  ask  ourselves  what  we 
mean  by  "best  results."  I  take  this  phrase  to 
refer  to  those  plants  which  are  best  fitted  to  sur- 
vive in  the  struggle  for  existence,  those  which  are 
most  vigorous  or  most  productive  or  most  hardy, 
or  which  possess  any  well-marked  character  or 
characters  which  distinguish  them  in  virility  from 
their  fellows.  We  commonly  associate  the  term 
more  particularly  with  marked  vigor  and  produc- 
tiveness ;  these  are  the  characters  most  useful  in 
nature  and  also  in  cultivation,  the  ones  which  we 
oftenest  desire  to  obtain.  Another  type  of  varia- 
tion which  we  constantly  covet  is  something  which 
we  can  call  a  new  character,  which  will  lead  to  the 
production  of  a  new  cultural  variety,  and  we  are 
always  looking  to  this  as  the  legitimate  result  of 
crossing.  We  have  forgotten  —  if,  indeed,  we  ever 
knew  —  that  the  commoner,  all-pervading,  more 
important  function  of  the  cross  is  to  infuse  some 
new  strength  or  power  into  the  offspring,  to  improve 
or  to  perpetuate  an  existing  variety,  rather  than  to 
create  a  new  one.     Or,  if  a  new  one  is  created,  it 


FUNCTION    OF    THE    CROSS.  51 

comes  from  the  gradual  passing  of  one  into  another, 
an  inferior  variety  into  a  good  one,  a  good  one  into 
a  superlative  one.  So  nature  employs  crossing  in 
a  process  of  slow  or  gradual  improvement,  one  step 
leading  to  another,  and  not  in  any  bold  or  sudden 
creation  of  new  forms.  And  there  is  evidence  to 
show  that  something  akin  to  this  must  be  done  to 
secure  the  best  and  most  permanent  results  under 
cultivation.  The  notion  is  somehow  firmly  rooted 
in  the  popular  mind  that  new  varieties  can  be  pro- 
duced with  the  greatest  ease  by  crossing  parents  of 
given  attributes.  There  is  something  captivating 
about  the  notion.  It  smacks  of  a  somewhat  magic 
power  which  man  evokes  as  he  passes  his  wand 
over  the  untamed  forces  of  nature.  But  the  wand 
is  often  only  a  gilded  stick,  and  is  apt  to  serve  no 
better  purpose  than  the  drum  major's  pretentious 
baton ! 

Let  me  say  further  that  crossing  alone  can 
accomplish  comparatively  little.  The  chief  power 
in  the  evolution  or  progression  of  plants  appears 
to  be  selection,  or,  as  Darwin  puts  it,  the  law  of 
"preservation  of  favorable  individual  differences 
and  variations,  and  the  destruction  of  those  which 
are  injurious."  Selection  is  the  force  which  aug- 
ments, develops,  and  fixes  types.  Man  must  not 
only  practice  a  judicious  selection  of  parents  from 
Avhich  the  cross  is  to  come,  which  is  in  reality  but 
the  exercise  of  a  choice,  but  he  must  constantly 


>Yl  PHILOSOPHY    OF   CROSSING   PLANTS. 

select  the  best  from  among  the  crosses,  in  order  to 
maintain  a  high  degree  of  usefulness  and  to  make 
any  advancement ;  and  it  sometimes  happens  that 
the  selection  is  much  more  important  to  the  culti- 
vator than  the  crossing.  I  do  not  wish  to  discour- 
age the  crossing  of  plants,  but  I  do  desire  to  dispel 
the  charm  which  too  often  hangs  about  it. 

Further  discussion  of  this  subject  naturally  falls 
under  two  heads :  the  improvement  of  existing 
types  or  varieties  by  means  of  crossing,  and  the 
summary  production  of  new  varieties.  I  have 
already  stated  that  the  former  office  is  the  more 
important  one,  and  the  proposition  is  easy  of  proof. 
It  is  the  chief  use  which  nature  makes  of  crossing, 
—  to  strengthen  the  type.  Think,  for  instance,  of 
the  great  rarity  of  hybrids  or  pronounced  crosses 
in  nature.  No  doubt  all  the  authentic  cases  on 
record  could  be  entered  in  one  or  two  volumes,  but 
a  list  of  all  the  individual  plants  of  the  world 
could  not  be  compressed  into  ten  thousand  volumes. 
There  are  a  few  genera,  in  which  the  species  are 
not  well  denned  or  in  which  some  character  of 
inflorescence  favors  promiscuous  crossing,  in  which 
hybrids  are  conspicuous ;  but  even  here  the  num- 
ber of  individual  hybrids  is  very  small  in  compari- 
son to  the  whole  number  of  individuals.  That  is, 
the  hybrids  are  rare,  while  the  parents  may  be 
common.  This  is  well  illustrated  even  in  the 
willows  and  oaks,  in  which,  perhaps,  hybrids  are 


RARITY    OF    HYBRIDS.  53 

better  known  than  in  any  other  American  plants. 
The  great  genus  carex  or  sedge,  which  occurs  in 
great  numbers  and  many  species  in  almost  every 
locality  in  New  England,  and  in  which  the  species 
are  particularly  adapted  to  intercrossing  by  the 
character  of  their  inflorescence,  furnishes  but  few 
undoubted  hybrids.  Among  one  hundred  and 
eighty-five  species  and  prominent  varieties  inhabit- 
ing the  northeastern  states,  there  are  only  eleven 
hybrids  recorded,  and  all  of  them  are  rare  or  local, 
some  of  them  having  been  collected  but  once. 
Species  of  carex  of  remarkable  similarity  may  grow 
side  by  side  for  years,  even  intertangled  in  the 
same  clump,  and  yet  produce  no  hybrid.  These 
instances  prove  that  nature  avoids  hybridization, 
—  a  conclusion  at  which  we  have  already  arrived 
from  philosophical  considerations.  And  Ave  have 
reason  to  infer  the  same  conclusion  from  the  fact 
that  flowers  of  different  species  are  so  constructed 
as  not  to  invite  intercrossing.  But,  on  the  other 
hand,  the  fact  that  all  higher  plants  habitually 
propagate  by  means  of  seeds,  which  is  far  the  most 
expensive  to  the  plant  of  all  methods  of  propa- 
gation, while  at  the  same  time  most  flowers  are  so 
constructed  as  to  prevent  self-fertilization,  proves 
that  some  corresponding  good  must  come  from 
crossing  within  the  limits  of  the  species  or  variety ; 
and  there  are  purely  philosophical  reasons,  as  we 
have   seen,   which   warrant   a   similar   conclusion. 


54  PHILOSOPHY    OF   CROSSING   PLANTS. 

But  experiment  has  given  us  more  direct  proof  of 
our  propositions,  and  we  shall  now  turn  our  atten- 
tion to  the  garden. 

Darwin  was  the  first  to  show  that  crossing  within 
the  limits  of  the  species  or  variety  results  in  a  con- 
stant revitalizing  of  the  offspring,  and  that  this  is 
the  particular  ultimate  function  of  cross-fertiliza- 
tion. Kolreuter,  Sprengel,  Knight,  and  others  had 
observed  many,  if,  indeed,  not  all,  the  facts  obtained 
by  Darwin ;  but  they  had  not  generalized  upon 
them  broadly,  and  did  not  conceive  their  relation 
to  the  complex  life  of  the  vegetable  world.  Dar- 
win's results  are,  concisely,  these  ;  self-fertilization 
tends  to  weaken  the  offspring ;  crossing  between 
different  plants  of  the  same  variety  gives  stronger 
and  more  productive  offspring  than  arises  from 
self-fertilization ;  crossing  between  stocks  of  the 
same  variety  grown  in  different  places  or  under  dif- 
ferent conditions  gives  better  offspring  than  cross- 
ing between  different  plants  grown  in  the  same 
place  or  under  similar  conditions ;  and  his  re- 
searches have  also  shown  that,  as  a  rule,  flowers 
are  so  constructed  as  to  favor  cross-fertilization. 
In  short,  he  found,  as  he  expressed  it,  that  "  nature 
abhors  perpetual  self-fertilization."  Some  of  his 
particular  results,  although  often  quoted,  will  be 
useful  in  fixing  these  facts  in  our  minds.  Plants 
from  crossed  seeds  of  morning-glory  exceeded  in 
height  those  from  self-fertilized  seeds  as  100  exceeds 


INCREASED    VIGOR    OF   CROSS-BREEDS.         55 

76,  in  the  first  generation.  Some  flowers  from  these 
plants  were  self-pollinated  and  some  were  crossed, 
and  in  this  second  generation  the  crossed  plants 
were  to  the  uncrossed  as  100  is  to  79 ;  the  opera- 
tion was  again  repeated,  and  in  the  third  generation 
the  figures  stand  100  to  68 ;  fourth  generation,  the 
plants  having  been  grown  in  midwinter,  when  none 
of  them  did  well,  100  to  86 ;  fifth  generation,  100 
to  75  ;  sixth  generation,  100  to  72  ;  seventh  genera- 
tion, 100  to  81  ;  eighth  generation,  100  to  85  ;  ninth 
generation,  100  to  79  ;  tenth  generation,  100  to 
54.  The  average  total  gain  in  height  of  the 
crossed  over  the  uncrossed  was  as  100  to  77,  or 
about  30  per  cent.  There  was  a  corresponding 
gain  in  fertility,  or  the  number  of  seeds  and  seed- 
pods  produced.  Yet,  striking  as  the  results  are, 
they  were  produced  by  simply  crossing  between 
plants  grown  near  together,  and  under  what  would 
ordinarily  be  called  uniform  conditions.  In  order 
to  determine  the  influence  of  crossing  with  fresh 
stock,  plants  of  the  same  variety  were  obtained 
from  another  garden,  and  these  were  crossed  with 
the  ninth  generation  mentioned  above.  The  off- 
spring of  this  cross  exceeded  those  of  the  other 
crossed  plants  as  100  exceeds  78,  in  height;  as  100 
exceeds  57,  in  the  number  of  seed-pods  ;  and  as  100 
exceeds  51,  in  the  weight  of  the  seed-pods.  In 
other  words,  crosses  between  fresh  stock  of  the  same 
variety  were  nearly  30  per  cent  more  vigorous  than 


56  PHILOSOPHY    OF   CROSSING   PLANTS. 

crosses  between  plants  grown  side  by  side  for  some 
time  and  over  44  per  cent  more  vigorous  than 
plants  from  self-fertilized  seeds.  On  the  other 
hand,  experiments  showed  that  crosses  between 
different  flowers  upon  the  same  plant  gave  actu- 
ally poorer  results  than  offspring  of  self-fertilized 
flowers.  It  is  evident,  from  all  these  figures,  that 
nature  desires  crosses  between  plants,  and,  if  pos- 
sible, between  plants  grown  under  somewhat  dif- 
ferent conditions.  All  the  results  are  exceedingly 
interesting  and  important;  and  there  is  every 
reason  to  believe  that,  as  a  rule,  similar  results  can 
be  obtained  with  all  plants. 

Darwin  extended  his  investigations  to  many 
plants,  only  a  few  of  which  need  be  discussed  here. 
Cabbage  gave  pronounced  results.  Crossed  plants 
were  to  self-fertilized  plants  in  weight  as  100  is 
to  37.  A  cross  was  now  made  between  these 
crossed  plants  and  a  plant  of  the  same  variety 
from  another  garden,  and  the  difference  in  weight 
of  the  resulting  offspring  was  the  difference  be- 
tween 100  and  22,  showing  a  gain  of  over  350  per 
cent,  due  to  a  cross  with  fresh  stock.  Crossed 
lettuce  plants  exceeded  uncrossed  in  height  as 
100  exceeds  82.  Buckwheat  gave  an  increase  in 
weight  of  seeds  as  100  to  82,  and  in  height  of 
plants  as  100  to  69.  Beets  gave  an  increase  in 
height  represented  by  100  and  87.  Maize,  when 
full   grown,    from    crossed   and   uncrossed   seeds, 


INCREASED    VIGOR    OF   CROSS-BREEDS.  57 

gave  the  differences  in  height  between  100  and  91. 
Canary-grass  gave  similar  results. 

I  have  obtained  results  as  well  marked  as  these 
upon  a  large  and  what  might  be  called  a  commer- 
cial scale.  I  raised  the  plants  during  the  first 
generation  of  seeds  from  known  parentage,  the 
flowers  from  which  they  came  having  been  care- 
fully pollinated  by  hand.  In  some  instances  the 
second  generations  were  grown  from  hand-crossed 
seeds,  but  in  other  cases  the  second  generations 
were  grown  from  seeds  simply  selected  from  the 
first-year  patches.  As  the  experiments  have  been 
made  in  the  field  and  upon  a  somewhat  extensive 
scale,  it  was  not  possible  to  accurately  measure 
the  plants  and  the  fruits  from  individuals  in  all 
cases ;  but  the  results  have  been  so  marked  as  to 
admit  of  no  doubt  as  to  their  character.  In  1889 
several  hand-crosses  were  made  among  egg-plants. 
Three  fruits  matured,  and  the  seeds  from  them 
were  grown  in  1890.  Some  two  hundred  plants 
were  grown,  and  they  were  characterized  through- 
out the  season  by  great  sturdiness  and  vigor  of 
growth.  They  grew  more  erect  and  taller  than 
other  plants  near  by  grown  from  commercial  seeds. 
They  were  the  finest  plants  which  I  had  ever  seen. 
It  was  impossible  to  determine  productiveness, 
from  the  fact  that  our  seasons  are  too  short  for 
egg-plants,  and  only  the  earliest  flowers,  in  the 
large  varieties,  perfect  their  fruit,  and  the  plant 


58  PHILOSOPHY    OF   CROSSING   PLANTS. 

blooms  continuously  through  the  season.  In  order 
to  determine  how  much  a  plant  will  bear,  it  must 
be  grown  until  it  ceases  to  bloom.  When  frost 
came,  I  could  see  little  difference  in  productive- 
ness between  these  crossed  plants  and  commercial 
plants.  A  dozen  fruits  were  selected  from  various 
parts  of  this  patch,  and  in  1891  about  twenty-five 
hundred  plants  were  grown  from  them.  Again 
the  plants  were  remarkably  robust  and  healthy, 
with  fine  foliage,  and  they  grew  erect  and  tall,  — 
an  indication  of  vigor.  They  were  also  very  pro- 
ductive ;  but,  as  the  cross  had  been  made  between 
unlike  varieties,  and  the  offsprings  were  therefore 
unlike  either  parent,  I  could  not  make  an  accurate 
comparison.  But  they  compared  well  with  com- 
mercial egg-plants,  and  I  am  satisfied  that  they 
would  have  shown  themselves  to  be  more  produc- 
tive than  common  stock  could  they  have  grown  a 
month  or  six  weeks  longer.  Professor  Munson,  of 
the  Maine  Agricultural  College,  grew  some  of  this 
crossed  stock  in  1891,  and  he  told  me  that  it  was 
better  than  any  commercial  stock  in  his  gardens. 

In  extended  experiments  in  the  crossing  of 
pumpkins,  squashes,  and  gourds,  carried  on  dur- 
ing several  years,  increase  in  productiveness  due 
to  crossing  has  been  marked  in  many  instances. 
Marked  increase  in  productiveness  has  been  ob- 
tained from  tomato  crosses,  even  when  no  other 
results  of  crossing  could  be  seen. 


BENEFITS   FROM   CHANGE    OF   SEED.  59 

b.    Change  of  Seed  and   Crossing. 

Bearing  in  mind  these  good  influences  of  cross- 
ing, let  us  recall  another  series  of  facts  following 
the  simple  change  of  seed.  Almost  every  farmer 
and  gardener  at  the  present  day  feel  that  an 
occasional  change  of  seed  results  in  better  crops, 
and  there  are  definite  records  to  show  that  such 
is  often  the  case.  In  fact,  I  am  convinced  that 
much  of  the  rapid  improvement  in  fruits  and  vege- 
tables in  recent  years  is  due  to  the  practice  of 
buying  plants  and  seeds  so  largely  of  dealers,  by 
means  of  which  the  stock  is  often  changed.  Even 
a  slight  change,  as  between  farms  or  neighboring 
villages,  sometimes  produces  marked  results,  such 
as  more  vigorous  plants  and  often  more  fruitful 
ones.  We  must  not  suppose,  however,  that  be- 
cause a  small  change  gives  a  good  result,  a  violent 
or  very  pronounced  change  gives  a  better  one. 
There  are  many  facts  on  record  to  show  that  great 
changes  often  profoundly  influence  plants,  and 
when  such  influence  results  in  lessened  vigor  or 
lessened  productiveness  we  call  it  an  injurious  one. 
Now,  this  injurious  influence  may  result  even 
when  all  the  conditions  in  the  new  place  are 
favorable  to  the  health  and  development  of  the 
plant ;  it  is  an  influence  which  is  wholly  indepen- 
dent, so  far  as  we  can  see,  of  any  condition  which 
interferes  injuriously  with  the  simple  processes  of 


60  PHILOSOPHY   OF    CROSSING   PLANTS. 

growth.  Seeds  of  a  native  physalis  or  husk-tomato 
were  sent  to  me  from  Paraguay  in  1889  by  Dr. 
Thomas  Moroug,  then  travelling  in  that  country. 
I  grew  it  both  in  the  house  and  out  of  doors,  and 
for  two  generations  was  unable  to  make  it  set 
fruit,  even  though  the  flowers  were  hand-polli- 
nated; yet  the  plants  were  healthy  and  grew 
vigorously.  The  third  generation  grown  out  of 
doors  set  fruit  freely.  This  is  an  instance  of  the 
fact  that  very  great  changes  of  conditions  may 
injuriously  affect  the  plant,  and  an  equally  good 
illustration  of  the  power  to  overcome  these  condi- 
tions. Now,  there  is  great  similarity  between  the 
effects  of  slight  and  violent  changes  of  conditions 
and  small  and  violent  degrees  of  crossing,  as  both 
Darwin  and  Wallace  have  pointed  out,  and  it  is 
pertinent  to  this  discussion  to  endeavor  to  dis- 
cover why  this  similarity  exists. 

It  is  well  proved  that  crossing  is  good  for  the 
resulting  offspring,  because  the  differences  be- 
tween the  parents  carry  over  new  combinations 
of  characters  or  at  least  new  powers  into  the 
crosses.  It  is  a  process  of  revitalization,  and  the 
more  different  the  stocks  in  desirable  characters 
within  the  limits  of  the  variety,  the  greater  is 
the  revitalization ;  and  frequently  the  good  is  of 
a  more  positive  kind,  resulting  in  pronounced 
characters  which  may  serve  as  the  basis  for  new 
varieties.     In  the  cross,  therefore,  a  new  combina- 


BENEFITS    FROM    CHANGE   OF    SEED.  61 

tion  of  characters  or  a  new  power  fit  it  to  live 
better  than  its  parents  in  the  conditions  under 
which  they  lived. 

In  the  case  of  change  of  stock  Ave  find  just  the 
reverse,  which,  however,  amounts  to  the  same 
thing,  —  that  the  same  characters  or  powers  fit  the 
plant  to  live  better  in  conditions  new  to  it  than 
plants  Avhich  have  long  lived  in  those  conditions. 
In  either  case,  the  good  comes  from  the  fitting 
together  of  new  characters  or  powers  and  new 
environments.  Plants  which  live  during  many 
generations  in  one  place  become  accustomed  to  the 
place,  thoroughly  fitted  into  its  conditions,  and  are 
in  what  Mr.  Spencer  calls  a  state  of  equilibrium. 
When  either  plant  or  conditions  change,  new  ad- 
justments must  take  place  ;  and  the  plant  may  find 
an  opportunity  to  take  advantage,  to  expand  in 
some  direction  in  which  it  has  before  been  held 
back ;  for  plants  always  possess  greater  power 
than  they  are  able  to  express.  "  These  rhythmical 
actions  or  functions  [of  the  organism],"  writes 
Spencer,  "and  the  various  compound  rhythms 
resulting  from  their  combinations,  are  in  such 
adjustment  as  to  balance  the  actions  to  which 
the  organism  is  subject.  There  is  a  constant  or 
periodic  genesis  of  forces  which,  in  their  kinds, 
amounts,  and  directions,  suffice  to  antagonize  the 
forces  which  the  organism  has  constantly  or  peri- 
odically to  bear.     If,  then,  there  exists  this  state 


62  PHILOSOPHY   OF   CROSSING   PLANTS. 

of  moving  equilibrium  among  a  definite  set  of 
internal  actions,  exposed  to  a  definite  set  of  ex- 
ternal actions,  what  must  result  if  any  of  the 
external  actions  are  changed  ?  Of  course  there  is 
no  longer  an  equilibrium.  Some  force  which  the 
organism  habitually  generates  is  too  great  or  too 
small  to  balance  some  incident  force ;  and  there 
arises  a  residuary  force  exerted  by  the  environ- 
ment on  the  organism,  or  by  the  organism  on  the 
environment.  This  residuary  force,  this  unbal- 
anced force,  of  necessity  expends  itself  in  produc- 
ing some  change  of  state  in  the  organism." 

The  good  results,  therefore,  are  processes  of 
adaptation,  and  when  adaptation  is  perfectly  com- 
plete the  plant  may  have  gained  no  permanent 
advantage  over  its  former  condition,  and  new 
crossing  or  another  change  may  be  necessaiy ;  yet 
there  is  often  a  permanent  gain,  as  when  a  plant 
becomes  visibly  modified  by  change  to  another  cli- 
mate. Now,  this  adaptive  change  may  express 
itself  in  two  ways  :  either  by  some  direct  influence 
upon  the  stature,  vigor,  or  other  general  character, 
or  indirectly  upon  the  reproductive  powers,  by 
which  some  new  influence  is  carried  to  the  off- 
spring. If  the  direct  influences  become  heredi- 
tary, as  observation  seems  to  show  may  sometimes 
occur,  the  two  directions  of  modification  may 
amount,  ultimately,  to  the  same  thing. 

For  the  purposes  of  this  discussion  it  is  enough 


CHANGE    OF    STOCK   AND    CROSSING.  63 

to  know  that  crossing  within  the  variety  and 
change  of  stock  within  ordinary  bounds  are  bene- 
ficial, that  the  results  in  the  two  cases  seem  to 
flow  from  essentially  the  same  causes,  and  that 
crossing  and  change  of  stock  combined  give  much 
better  results  than  either  one  alone ;  and  this 
benefit  is  expressed  more  in  increased  yield  and 
vigor  than  in  novel  and  striking  variations.  These 
processes  are  much  more  important  than  any  mere 
groping  after  new  varieties,  as  I  have  already  said; 
not  only  because  they  are  surer,  but  because  they 
are  universal  and  necessary  means  of  maintaining 
and  improving  both  wild  and  cultivated  plants. 
Even  after  one  succeeds  in  securing  and  fixing 
a  new  variety,  he  must  employ  these  means  to  a 
greater  or  less  extent  to  maintain  fertility  and 
vigor,  and  to  keep  the  variety  true  to  its  type. 
In  the  case  of  some  garden  crops,  in  which  many 
seeds  are  produced  in  each  fruit  and  in  which 
the  operation  of  pollination  is  easy,  actual  hand- 
crossing  from  new  stock  now  and  then  may  be 
found  to  be  profitable.  But  in  most  cases  the 
operation  can  be  left  to  nature,  if  the  new  stock 
is  planted  among  the  old.  Upon  this  point  Dar- 
win expressed  himself  as  follows  :  "  It  is  a  common 
practice  with  horticulturists  to  obtain  seeds  from 
another  place  having  a  very  different  soil,  so  as  to 
avoid  raising  plants  for  a  long  succession  of  gen- 
erations under  the  same  conditions ;  but  with  all 


(J4  PHILOSOPHY   OF   CROSSING   PLANTS. 

the  species  which  freely  intercross  by  the  aid  of 
insects  or  the  wind,  it  would  be  an  incomparably 
better  plan  to  obtain  seeds  of  the  required  variety, 
which  had  been  raised  for  some  generations  under 
as  different  conditions  as  possible,  and  sow  them 
in  alternate  rows  with  seeds  matured  in  the  old 
garden.  The  two  stocks  would  then  intercross, 
with  a  thorough  blending  of  their  whole  organi- 
zations, and  with  no  loss  of  purity  to  the  variety, 
and  this  would  yield  far  more  favorable  results 
than  a  mere  change  of  seed." 

c.    The    Outright  Production  of  Neiv  Varieties. 

But  you  are  waiting  for  a  discussion  of  the 
second  of  the  great  features  of  crossing, — the  sum- 
mary production  of  new  varieties,,  This  is  the  sub- 
ject which  is  almost  universally  associated  with 
crossing  in  the  popular  mind,  and  even  among 
horticulturists  themselves.  It  is  the  commonest 
notion  that  the  desirable  characters  of  given 
parents  can  be  definitely  combined  in  a  pronounced 
cross  or  hybrid.  There  are  two  or  three  philo- 
sophical reasons  which  somewhat  oppose  this  doc- 
trine, and  which  we  will  do  well  to  consider  at  the 
outset.  In  the  first  place,  nature  is  opposed  to 
hybrids,  for  species  have  been  bred  away  from  each 
other  in  the  ability  to  cross.  If,  therefore,  there 
is  no  advantage  for  nature  to  hybridize,  we  may 


PRODUCTION    OF   NOVELTIES.  65 

suppose  that  there  would  be  little  advantage  for 
man  to  do  so ;  and  there  would  be  no  advantage 
for  man  did  he  not  place  the  plant  under  conditions 
different  from  nature,  or  desire  a  different  set  of 
characters.  We  have  seen  that  nature's  chief 
barriers  to  hybridization  are  total  refusal  of  species 
to  unite,  and  entire  or  comparative  seedlessness 
of  offspring.  We  can  overcome  the  refusal  to 
cross  in  many  cases  by  bringing  the  plant  under 
cultivation ;  for  the  character  of  the  species  be- 
comes so  changed  by  the  wholly  new  conditions 
that  its  former  antipathies  may  be  overpowered. 
Yet  it  is  doubtful  if  such  a  plant  will  ever  acquire 
a  complete  willingness  to  cross.  In  like  manner 
we  can  overcome  in  a  measure  the  comparative 
seedlessness  of  hybrids,  but  it  is  very  doubtful  if 
Ave  can  ever  make  such  hybrids  completely  fruit- 
ful. It  would  appear,  therefore,  upon  theoretical 
grounds,  that  in  plants  in  which  seeds  are  the  parts 
sought,  no  good  can  be  expected,  as  a  rule,  from 
hybridization ;  and  this  seems  to  be  affirmed  by 
facts.1 

It  is  evident  that  species  which  have  been 
differentiated  or  bred  away  from  each  other  in 
a  given  locality  will  have  more  opposed  qualities 
or  powers  than  similar  species  which  have  arisen 
quite  independently  in  places   remote  from  each 

1  See  definition  of  hybrids,  crosses,  and  other  terms  in  the 
Glossary. 


bb  PHILOSOPHY   OF   CROSSING   PLANTS. 

other.  In  the  one  case  the  species  have  likely 
struggled  with  each  other  until  each  one  has  at- 
tained to  a  degree  of  divergence  which  allows  it 
to  persist ;  while  in  the  other  case  there  has  been 
no  struggle  between  the  species,  but  similar  con- 
ditions have  brought  about  similar  results.  These 
similar  species  which  appear  independently  of 
each  other  in  different  places  are  called  representa- 
tive species.  Islands  remote  from  each  other  but 
similarly  situated  with  reference  to  climate  very 
often  contain  representative  species  ;  and  the  same 
may  be  said  of  other  regions  much  like  each  other, 
as  eastern  North  America  and  Japan.  Now,  it 
follows  that,  if  representative  species  are  less 
opposed  than  others,  they  are  more  likely  to 
hybridize  with  good  results  ;  and  this  fact  is  re- 
markably well  illustrated  in  the  KiefTer  and  allied 
pears,  which  are  hybrids  between  representative 
species  of  Europe  and  Japan  ;  and  I  am  inclined 
to  think  that  the  same  may  be  found  to  be  true 
of  the  common  or  European  apple  and  the  wild 
crab  of  the  Mississippi  valley.  Various  crabs  of 
the  Soulard  type,  which  I  once  thought  to  con- 
stitute a  distinct  species,  appear  upon  further  study 
to  be  hybrids.  We  will  also  recall  that  the  hybrid 
grapes  which  have  so  far  proved  most  valuable  are 
those  obtained  by  Rogers  between  the  American 
Vitis  Labrusca  and  the  European  wine  grape  ;  and 
that  the  attempts  of  Haskell  and  others  to  hybrid- 


INSTABILITY   OF    HYBBIDS.  67 

ize  associated  species  of  native  grapes  have  given, 
at  best,  only  indifferent  results.  To  these  good 
results  from  hybrids  of  fruit  trees  and  vines  I 
shall  revert  presently. 

Another  theoretical  point,  which  is  borne  out 
by  practice,  is  the  conclusion  that,  because  of  the 
great  differences  and  lack  of  affinity  between  par- 
ents, pronounced  hybrid  offsprings  are  unstable. 
This  is  one  of  the  greatest  difficulties  in  the  way 
of  the  summary  production  of  new  varieties  by 
means  of  hybridization.  It  would  appear,  also, 
that,  because  of  the  unlikeness  of  parents,  hybrid 
offspring  must  be  exceedingly  variable  ;  but,  as 
a  matter  of  fact,  in  many  instances  the  parents 
are  so  pronouncedly  different  that  the  hybrids 
represent  a  distinct  type  by  themselves,  or  else 
they  approach  very  nearly  to  the  characters  of 
one  of  the  parents.  There  are,  to  be  sure,  many 
instances  of  exceedingly  variable  hybrid  offspring, 
but  they  are  usually  the  offspring  of  variable  par- 
ents. In  other  words,  variability  in  offspring 
appears  to  follow  rather  as  a  result  of  variability 
in  parents  than  as  a  result  of  mere  unlikeness 
of  characters.  But  the  instability  of  hybrid  off- 
spring when  propagated  by  seed  is  notorious. 
Wallace  writes  that  "  the  effect  of  occasional 
crosses  often  results  in  a  great  amount  of  varia- 
tion, but  it  also  leads  to  instability  of  character, 
and    is    therefore    very   little    employed    in    the 


68  PHILOSOPHY   OF    CROSSING   PLANTS. 

production  of  fixed  and  well-marked  races."  I 
may  remark  again  that,  because  of  the  unequal 
and  unknown  powers  of  the  parents,  we  can  never 
predict  what  characters  will  appear  in  the  hybrids. 
This  fact  was  well  expressed  by  Lindley  a  half 
century  ago,  in  the  phrase,  "  Hybridizing  is  a 
game  of  chance  played  between  man  and  plants." 

V.   Characteristics  of  Crosses. 

Bearing  these  fundamental  propositions  in  mind, 
let  us  pursue  the  subject  somewhat  in  detail. 
We  shall  find  that  the  characters  of  hybrids, 
as  compared  with  the  characters  of  simple  crosses 
between  stocks  of  the  same  variety,  are  ambiguous, 
negative,  and  often  prejudicial.  The  fullest  dis- 
cussion of  hybrids  has  been  made  by  Focke  (see 
Lecture  IV.),  and  he  lays  down  the  five  following 
propositions  concerning  the  character  of  hybrid 
offspring :  — 

1.  "  All  individuals  which  have  come  from  the 
crossing  of  two  pure  species  or  races,  when  pro- 
duced and  grown  under  like  conditions,  are 
usually  exactly  like  each  other,  or  at  least  scarcely 
more  different  from  each  other  than  plants  of  the 
same  species  are."  This  proposition,  although 
perhaps  true  in  the  main,  appears  to  be  too 
broadly  and  positively  stated. 

2.  "  The  characters  of  hybrids  may  be  different 


HYBRIDS    AND    CROSS-BREEDS.  69 

from  the  characters  of  the  parents.  The  hybrids 
differ  most  in  size  and  vigor  and  in  their  sexual 
powers." 

3.  "  Hybrids  are  distinguished  from  their  par- 
ents by  their  powers  of  vegetation  or  growth. 
Hybrids  between  very  different  species  are  often 
weak,  especially  when  young,  so  that  it  is  difficult 
to  raise  them.  On  the  other  hand,  cross-breeds 
are,  as  a  rule,  uncommonly  vigorous ;  they  are  dis- 
tinguished mostly  by  size,  rapidity  of  growth,  early 
flowering,  productiveness,  longer  life,  stronger 
reproductive  power,  unusual  size  of  some  special 
organs,  and  similar  characteristics." 

4.  "  Hybrids  produce  a  less  amount  of  pollen 
and  fewer  seeds  than  their  parents,  and  they 
often  produce  none.  In  cross-breeds  this  weaken- 
ing of  the  reproductive  powers  does*  not  occur. 
The  flowers  of  sterile  or  nearly  sterile  hybrids 
usually  remain  fresh  a  long  time." 

5.  "  Malformations  and  odd  forms  are  apt  to 
appear  in  hybrids,  especially  in  the  flowers." 

Some  of  the  relations  between  hybridization 
and  crossing  within  narrow  limits  are  stated  as 
follows  by  Darwin  :  "  It  is  an  extraordinary  fact 
that  with  many  species  flowers  fertilized  with 
their  own  pollen  are  either  absolutely  or  in  some 
degree  sterile ;  if  fertilized  with  pollen  from 
another  flower  on  the  same  plant,  they  are  some- 
times,   though   rarely,    a   little    more    fertile ;    if 


70  PHILOSOPHY    OF    CROSSING   PLANTS. 

fertilized  with  pollen  from  another  individual 
or  variety  of  the  same  species,  they  are  fully 
fertile ;  but  if  with  pollen  from  a  distinct  species, 
they  are  sterile  in  all  possible  degrees,  until  utter 
sterility  is  reached.  We  thus  have  a  long  series 
with  absolute  sterility  at  the  two  ends ;  at  one 
end  due  to  the  sexual  elements  not  having  been 
sufficiently  differentiated,  and  at  the  other  end 
to  their  having  been  differentiated  in  too  great 
a  degree,  or  in  some  peculiar  manner." 

The  difficulties  in  the  way  of  successful  results 
through  hybridization  are,  therefore,  these :  the 
difficulty  of  effecting  the  cross ;  infertility,  in- 
stability, variability,  and  often  weakness  and 
monstrosity  of  the  hybrids ;  and  the  absolute  im- 
possibility of  predicting  results.  The  advantage 
to  be  derived  from  a  successful  hybridization  is 
the  securing  of  a  new  variety  which  shall  combine 
in  some  measure  the  most  desirable  features  of 
both  parents ;  and  this  advantage  is  often  of  so 
great  moment  that  it  is  worth  while  to  make  re- 
peated efforts  and  to  overlook  numerous  failures. 
From  these  theoretical  considerations  it  is  apparent 
that  hybridization  is  essentially  an  empirical  sub- 
ject, and  the  results  are  such  as  fall  under  the 
common  denomination  of  chance.  And,  as  it  does 
not  rest  upon  any  legitimate  function  in  nature, 
we  can  understand  that  it  will  always  be  difficult 
to  codify  laws  upon  it. 


HYBRIDS    AND    BUD-PROPAGATION.  71 

Among  the  various  characters  of  hybrid  off- 
spring, I  presume  that  the  most  prejudicial  one  is 
their  instability,  their  tendency  still  to  vary  into 
new  forms  or  to  return  to  one  or  the  other  parent 
in  succeeding  generations.  It  is  difficult  to  fix 
any  particular  form  which  we  may  secure  in  the 
first  generation  of  hybrids.  At  the  outset,  we 
notice  that  this  discouraging  feature  is  manifested 
chiefly  through  the  fact  of  seed-reproduction,  and 
we  thereby  come  upon  what  is  perhaps  the  most 
important  practical  consideration  in  hybridization, 
—  the  fact  that  the  great  majority  of  the  best 
hybrids  in  cultivation  are  increased  by  bud-propa- 
gation, as  cuttings,  layers,  suckers,  buds,  or  grafts. 
In  fact,  I  recall  very  few  instances  in  this  country 
of  good  undoubted  hybrids  which  are  propagated 
with  practical  certainty  by  means  of  seeds.  You 
will  recall  that  the  genera  in  which  hybrids  are 
most  common  are  those  in  which  bud-propagation 
is  the  rule ;  as  begonia,  pelargonium,  orchids, 
gladiolus,  rhododendron,  roses,  cannas,  and  the 
fruits.  This  simply  means  that  it  is  difficult  to 
fix  hybrids  so  that  they  will  come  "  true  to  seed," 
and  makes  apparent  the  fact  that  if  we  desire 
hybrids  we  must  expect  to  propagate  them  by 
means  of  buds. 

This  is  a  point  which  appears  to  have  been  over- 
looked by  those  who  contend  that  hybridization 
must  necessarily  swamp  all  results  of  natural  se- 


72  PHILOSOPHY   OF    CROSSING   PLANTS. 

lection  ;  for,  as  comparatively  few  plants  propagate 
habitually  by  means  of  buds,  whatever  hybrids 
might  have  appeared  would  have  been  speedily 
lost,  and  all  the  more,  also,  because,  by  the  terms 
of  their  reasoning,  the  hybrids  would  cross  with 
other  and  dissimilar  forms,  and  therefore  lose  their 
identity  as  intermediates.  Or,  starting  with  the 
assumption  that  hybrids  are  intermediates,  and 
would  therefore  obliterate  specific  types,  we  must 
conclude  that  they  should  have  some  marked  de- 
gree of  stability  if  they  are  to  swamp  or  obliterate 
the  characters  of  species ;  but,  as  all  hybrids  tend 
to  break  up  when  propagated  by  seeds,  it  must 
follow  that  bud-propagation  would  become  more 
and  more  common,  and  this  is  associated  in  nature 
with  decreased  seed-production.  Now,  seed-pro- 
duction is  the  legitimate  function  of  flowers ;  and 
we  must  concede  that,  as  seed-production  de- 
creased, floriferousness  must  have  decreased ;  and 
that,  therefore,  pronounced  intercrossing  would 
have  obliterated  the  very  organs  upon  which  it 
depends,  or  have  destroyed  itself  ! 

But  I  may  be  met  by  the  objection  that  there 
is  no  inherent  reason  why  hybrids  should  not 
become  stable  through  seed-production  by  in-breed- 
ing, and  I  might  be  cited  to  the  opinion  of  Darwin 
and  others  that  in-breeding  tends  to  fix  any  va- 
riety, whether  it  originates  by  crossing  or  other 
means.     And  it  is  a  fact  that  in-breeding  tends  to 


IN-BREEDING    OF    CROSSES.  73 

fix  varieties  within  certain  limits,  but  those  limits 
are  often  overpassed  in  the  case  of  very  pro- 
nounced crosses,  whether  cross-breeds  or  true 
hybrids.  And  if  it  is  true,  as  all  observation  and 
experiments  show,  that  sexual  or  reproductive 
powers  of  crosses  are  weakened  as  the  cross  be- 
comes more  violent,  we  should  expect  less  and  less 
possibility  of  successful  in-breeding ;  for  in-breed- 
ing without  disastrous  results  is  possible  only  with 
comparatively  strong  reproductive  powers.  As  a 
matter  of  fact,  it  is  found  in  practice  that  it  is 
exceedingly  difficult  to  fix  pronounced  hybrids  by 
means  of  in-breeding.  It  sometimes  happens,  too, 
that  the  hybrid  individual  which  Ave  wish  to  per- 
petuate may  be  infertile  with  itself,  as  I  have  often 
found  in  the  case  of  squashes.  It  is  often  advised 
that  we  cross  the  hybrid  individual  which  we  wish 
to  fix  with  another  like  individual,  or  with  one  of 
its  parents.  These  results  are  often  successful, 
but  oftener  they  are  not.  In  the  first  place,  it 
often  happens  that  the  hybrid  individuals  may  be 
so  diverse  that  no  two  of  them  are  alike ;  this  has 
been  my  experience  in  many  crosses.  And,  again, 
crossing  with  a  parent  may  draw  the  hybrid  back 
again  to  the  parental  form.  So  long  ago  as  last 
century  Kolreuter  proved  this  fact  upon  nicotiana 
and  dianthus.  A  hybrid  between  Nicotiana  rus- 
tica  and  N.  paniculata  was  crossed  with  N.  pani- 
culata  until  it  was  indistinguishable  from  it ;  and 


74  PHILOSOPHY   OF    CROSSING   PLANTS. 

it  was  then  crossed  with  N.  rustica  until  it  became 
indistinguishable  from  that  parent.  Yet  there  is 
no  other  way  of  fixing  a  hybrid  to  be  propagated 
by  seeds  than  by  in-breeding,  and  by  constant  at- 
tention to  selection.  Fortunately,  it  occasionally 
happens  that  a  hybrid  is  stable,  and  therefore 
needs  no  fixing. 

In  this  connection  I  may  cite  some  of  my  own 
experience  in  crossing  egg-plants  and  squashes ; 
for,  although  the  products  were  not  true  hybrids 
in  the  strict  interpretation  of  the  word,  many  of 
them  were  hybrids  to  all  intents  and  purposes, 
because  made  between  very  unlike  varieties,  and 
they  will  serve  to  illustrate  the  difficulties  of  which 
I  speak.  Offspring  of  egg-plant  crosses  were  grown 
in  1890,  and  upon  some  of  the  most  promising 
plants  some  flowers  were  self-pollinated.  But 
these  self-pollinated  seeds  gave  just  as  variable 
offspring  in  1891,  as  those  selected  almost  at 
random  from  the  patch;  and,  what  was  worse, 
none  of  them  reproduced  the  parent,  or  "  came 
true  to  seed,"  and  all  further  motive  for  in-breed- 
ing was  gone.  My  labor,  therefore,  amounted  to 
nothing  more  than  my  own  edification.  My 
experience  in  crossing  pumpkins  and  squashes  has 
now  extended  through  many  years ;  and,  although 
I  have  obtained  about  one  thousand  types  not 
named  or  described,  I  have  not  yet  succeeded  in 
fixing  one.     The  difficulty  here  is  an  aggravated 


EXPERIMENTS    IN    IN-BREEDING.  75 

one,  however.  The  species  are  so  exceedingly 
variable  that  all  the  hybrid  individuals  may  be 
unlike,  so  that  there  can  be  no  crossing  between 
identical  stocks  ;  and,  if  in-breeding  is  attempted, 
it  may  be  found  that  the  flowers  will  not  in-breed. 
And  the  refusal  to  in-breed  is  all  the  more  strange 
because  the  sexes  are  separated  in  different  flowers 
upon  the  same  plant.  In  other  words,  in  my  expe- 
rience, it  is  very  difficult  to  get  good  seeds  from 
squashes  which  are  fertilized  by  a  flower  upon  the 
same  vine.  The  squashes  may  grow  normally  to 
full  maturity,  but  be  entirely  hollow,  or  contain 
only  empty  seeds.  In  some  instances  the  seeds 
may  appear  to  be  good,  but  may  refuse  to  grow 
under  the  best  conditions.  Finally,  a  small  number 
of  flowers  may  give  good  seeds.  I  have  many 
times  observed  this  refusal  of  squashes  (Cucurbita 
Pepo)  to  in-breed.  It  was  first  brought  to  my 
attention  through  efforts  to  fix  certain  types  into 
varieties.  The  figures  of  one  season's  tests  will 
sufficiently  indicate  the  character  of  the  problem. 
In  1890,  one  hundred  and  eighty-five  squash  flowers 
were  carefully  pollinated  with  staminate  flowers 
taken  from  the  same  vine  which  bore  the  pistillate 
flowers.  Only  twenty-two  of  these  produced  fruit, 
and  of  these  only  seven,  or  less  than  one-third,  bore 
good  seeds,  and  in  some  of  these  the  seeds  were 
few.  Now,  these  twenty-two  fruits  represented  as 
many  different  varieties,  so  that  the  inability  to  set 


76  PHILOSOPHY   OF   CROSSING   PLANTS. 

fruit  with  pollen  from  the  same  vine  is  not  a 
peculiarity  of  a  particular  variety.  The  records 
of  the  seeds  of  the  seven  fruits  in  1891  are  as 
follows  :  — 

Fruit  No.  1.  —  Four  vines  were  obtained,  with 
four  different  types,  two  of  them  being  white,  one 
yellow,  and  one  black. 

Fruit  No.  2.  —  Twenty-three  vines.  Fifteen 
types  very  unlike,  twelve  being  white  and  three 
yellow. 

Fruit  No.  3.  —  Two  vines.  One  type  of  fruit 
Avhich  was  almost  like  one  of  the  original  parents. 

Fruit  No.  4.  —  Thirty-two  vines.  Six  types, 
differing  chiefly  in  size  and  shape. 

Fruit  No.  5.  —  Twent}^  vines.  Nineteen  types, 
of  which  ten  were  white,  eight  orange,  one  striped, 
and  all  very  unlike. 

Fruit  No.  6.  —  Thirteen  vines.  Eleven  types, 
—  eight  yellow,  two  black,  one  white. 

Fruit  No.  7.  —  One  vine. 

These  offspring  were  just  as  variable  as  those 
from  flowers  not  in-bred,  and  no  more  likely, 
apparently,  to  reproduce  the  parent.  These  tests 
leave  me  without  any  method  of  fixing  a  pro- 
nounced cross  of  squashes,  and  lead  me  to  think 
that  the  legitimate  process  of  origination  of  new 
kinds  here,  as,  indeed,  if  not  in  general,  is  a  more 
gradual  process  of  selection,  coupled,  perhaps,  with 
minor  crossing. 


ATTEMPT   TO   FIX   A   CROSS.  77 

I  will  relate  a  definite  attempt  towards  the  fixa- 
tion of  a  squash  which  I  had  obtained  from  cross- 
ing. The  history  of  it  runs  back  to  1887,  when  a 
cross  was  effected  between  a  summer  yellow  crook- 
neck  and  a  white  bush  scallop  squash.  In  1889 
there  appeared  a  squash  of  great  excellence,  com- 
bining the  merits  of  summer  and  winter  squashes 
with  very  attractive  form,  size,  and  color,  and  a 
good  habit  of  plant.  I  showed  the  fruit  to  one  of 
the  most  expert  seedsmen  of  the  country,  and  he 
pronounced  it  one  of  the  most  promising  types 
which  he  had  ever  seen  ;  and,  as  he  informed  me 
that  he  had  fixed  squashes  by  breeding  in  and  in, 
I  was  all  the  more  anxious  to  carry  out  my  own 
convictions  in  the  same  direction.  It  is  needless 
to  say  that  I  was  very  happy  over  what  I  regarded 
as  a  great  triumph.  Of  course  I  must  have  a  large 
number  of  plants  of  my  new  variety,  that  I  might 
select  the  best,  both  for  in-breeding  and  for  cross- 
ing similar  types.  So  I  selected  the  very  finest 
squash,  having  placed  it  where  I  could  admire  it 
for  some  days,  and  saved  every  seed  of  it.  These 
seeds  were  planted  upon  the  most  conspicuous 
knoll  in  my  garden  in  1890.  It  was  soon  evident 
that  something  was  wrong.  I  seemed  to  have 
everything  except  my  squash.  One  plant,  how- 
ever, bore  fruits  almost  like  the  parent,  and  upon 
this  I  began  my  attempts  towards  in-breeding. 
But  flower  after  flower  failed,  and  I  soon  saw  that 


78  PHILOSOPHY    OP    CROSSING   PLANTS. 

the  plant  was  infertile  with  itself.  Careful  search 
revealed  two  or  three  other  plants  very  like  this 
one,  and  I  then  proceeded  to  make  crosses  upon  it. 
I  was  equally  confident  that  this  method  would 
succeed.  When  I  harvested  my  squashes  in  the 
fall  and  took  account  of  stock,  I  found  that  the 
seeds  of  my  one  squash  had  given  just  as  many 
different  types  as  there  were  plants,  and  I  actually 
counted  one  hundred  and  ten  kinds  distinct  enough 
to  be  named  and  recognized.  Still  confident,  in 
1891  I  planted  the  seeds  of  my  few  crosses,  and  as 
the  summer  days  grew  long  and  the  crickets 
chirped  in  the  meadows,  I  watched  the  expanding 
squash  blossoms  and  wondered  what  they  would 
bring  forth.  But  they  brought  only  disappoint- 
ment. Not  one  seed  produced  a  squash  like  the 
parent.  My  squash  had  taken  an  unscientific 
leave  of  absence,  and  I  do  not  know  its  where- 
abouts. And  when  the  frost  came  and  killed 
every  ambitious  blossom,  my  hope  went  out  and 
has  not  yet  returned! 

Let  us  now  recall  how  many  undoubted  hybrids 
there  are,  named  and  known,  among  our  fruits 
and  vegetables.  In  grapes  there  are  the  most. 
There  are  Rogers'  hybrids,  like  the  Agawam, 
Lindley,  Wilder,  Salem,  and  Barry ;  and  there  is 
some  reason  for  supposing  that  the  Delaware, 
Catawba,  and  other  varieties  are  of  hybrid  origin. 
And  many  hybrids    have    come   to   notice    lately 


LIST    OF    COMMON   HYBRIDS.  79 

through  the  work  of  Munson  and  others.  But  it 
must  be  remembered  that  grapes  are  naturally  ex- 
ceedingly variable,  and  the  specific  limits  are  not 
well  known,  and  that  hybridization  among  them 
lacks  much  of  that  deflniteness  which  ordinarily 
attaches  to  the  subject.  In  pears  there  is  the 
Kieffer  class.  In  apples,  peaches,  plums,  cher- 
ries, gooseberries,  and  currants,  there  are  no  im- 
portant commercial  hybrids.  In  blackberries  there 
is  the  blackberry-dewberry  class,  represented  by 
the  Wilson  Early  and  others.  Some  of  the  rasp- 
berries, like  the  Philadelphia  and  Shaffer,  are  hy- 
brids between  the  red  and  black  species.  Hybrids 
have  been  produced  between  the  raspberry  and 
blackberry  by  two  or  three  persons,  but  they  pos- 
sess no  promise  of  economic  results.  Among  all 
the  list  of  garden  vegetables  (plants  which  are 
propagated  by  seeds)  I  do  not  know  of  a  single 
important  hybrid  ;  and  the  same  is  true  of  wheat, 
—  unless  the  Carman  wheat-rye  varieties  become 
prominent,  —  oats,  the  grasses,  and  other  farm 
crops.  But  among  ornamental  plants  there  are 
many ;  and  it  is  a  significant  fact  that  the  most 
numerous,  most  marked,  and  most  successful  hy- 
brids occur  in  the  plants  most  carefully  cultivated 
and  protected,  those,  in  other  words,  which  are 
farthest  removed  from  all  untoward  circumstances 
and  an  independent  position.  This  is  nowhere  so 
well  illustrated  as  in  the  case  of  cultivated  orchids, 


80  PHILOSOPHY    OF    CROSSING   PLANTS. 

in  which  hybridization  has  played  no  end  of  freaks, 
and  in  which,  also,  every  individual  plant  is  nursed 
and  coddled.1  With  such  plants  the  struggle  for 
existence  is  reduced  to  its  lowest  terms  ;  for  it 
must  be  borne  in  mind  that,  even  in  the  garden, 
plants  must  fight  severely  for  a  chance  to  live,  and 
even  then  only  the  very  best  can  persist,  or  are 
even  allowed  to  try. 

I  am  sure  that  this  list  of  hybrids  is  much  more 
meagre  than  most  catalogues  and  trade-lists  would 
have  us  believe,  but  I  am  sure  that  it  is  approxi- 
mately near  the  truth.  It  is,  of  course,  equivalent 
to  saying  that  most  of  the  so-called  hybrid  fruits 
and  vegetables  are  myths.  There  is  everywhere  a 
misconception  of  what  a  hybrid  is,  and  how  it 
comes  to  exist ;  and  yet,  perhaps  because  of  this 
indefinite  knowledge,  there  is  a  wide-spread  feel- 
ing that  a  hybrid  is  necessarily  good,  while  the 
presumption  is  directly  the  opposite.  The  identity 
of  a  hybrid  in  the  popular  mind  rests  entirely  upon 
some  superficial  character,  and  proceeds  upon  the 
assumption  that  it  is  necessarily  intermediate  be- 
tween the  parents.  Hence  we  find  one  of  our 
popular  authors  asserting  that,  because  the  kohl- 
rabi bears  its  thickened  portion  midway  of  its  stem, 
it  is  evidently  a  hybrid  between  the  cabbage  and 
turnip,  which  bear  respectively  the  thickened  parts 

1  Consult  E.  Bohnhof,  "  Dictioimaire  des  Orchid^es  Hy- 
brides,"  Paris,  1895. 


INFLUENCE    OF    PARENTS.  81 

at  the  opposite  extremities  of  the  stem  !  And  then 
there  are  those  who  confound  the  word  hybrid 
with  high-bred,  and  who  build  attractive  castles 
upon  the  unconscious  error.  And  thus  is  confu- 
sion confounded ! 

But,  before  leaving  this  subject  of  hybridization, 
I  must  speak  of  the  old  yet  common  notion  that 
there  is  some  peculiar  influence  exerted  by  each 
sex  in  the  parentage  of  hybrids  ;  for  I  shall  thereby 
not  only  call  your  attention  to  what  I  believe  to 
be  an  error,  but  shall  also  find  the  opportunity  to 
still  further  illustrate  the  entanglements  of  hybri- 
dization. It  was  held  by  certain  early  observers,  of 
whom  the  great  Linnaeus  was  one,  that  the  female 
parent  determines  the  constitution  of  the  hybrid, 
while  the  male  parent  gives  the  external  attributes, 
as  form,  size,  and  color.  The  accumulated  experi- 
ence of  nearly  a  century  and  a  half  appears  to  con- 
tradict this  proposition,  and  Focke,  who  has  recently 
gone  over  the  whole  ground,  positively  declares 
that  it  is  untrue.  There  are  instances,  to  be  sure, 
in  which  this  old  idea  is  affirmed,  but  there  are 
others  in  which  it  is  contradicted.  The  truth  ap- 
pears to  be  this,  —  that  the  parent  of  greater 
strength  or  virility  makes  the  stronger  impression 
upon  the  hybrids,  whether  it  is  the  staminate  or 
pistillate  parent;  and  it  appears  to  be  equally 
true  that  it  is  usually  impossible  to  determine  be- 
forehand which  parent  is  the  stronger.     It  is  cer- 


82  PHILOSOPHY    OF    CROSSING    PLANTS. 

tain  that  strength  does  not  lie  in  size,  neither  in 
the  high  development  of  any  character.  It  appears 
to  be  more  particularly  associated  with  what  we 
call  fixity  or  stability  of  character,  or  the  tendency 
towards  invariability. 

This  has  been  well  illustrated  in  my  own  experi- 
ments with  squashes,  gourds,  and  pumpkins.  The 
common  little  pear-shaped  gourd  will  impress  itself 
more  strongly  upon  crosses  than  any  of  the  edible 
squashes  and  pumpkins  with  which  it  will  effect  a 
cross,  whether  it  is  used  as  male  or  female  parent. 
Even  the  imposing  and  ubiquitous  great  field 
pumpkin,  which  every  New  Englander  associates 
with  pies,  is  overpowered  by  the  little  gourd. 
Seeds  from  a  large  and  sleek  pumpkin  which  had 
been  fertilized  by  gourd  pollen,  produced  gourds 
and  small  hard-shelled  globular  fruits  which  were 
entirely  inedible.  A  more  interesting  experiment 
was  made  between  the  handsome  green-striped  Ber- 
gen fall  squash  and  the  little  pear  gourd.  Several 
flowers  of  the  gourd  were  pollinated  by  the  Bergen 
in  1889.  The  fruits  raised  from  these  seeds  in 
1890  were  remarkably  gourd-like.  Some  of  these 
crosses  were  pollinated  again  in  1890  by  the  Ber- 
gen, and  the  seeds  were  sown  in  1891.  Here, 
then,  were  crosses  into  which  the  gourd  had  gone 
once  and  the  Bergen  twice,  and  both  the  parents 
are  to  all  appearances  equally  fixed,  the  difference 
in  strength,  if  any,  attaching  rather  to  the  Bergen. 


POLLINATION    IS    UNCERTAIN.  83 

Now,  the  crop  of  1891  still  carried  pronounced 
characters  of  the  gourd.  Even  in  the  fruits  which 
most  resembled  the  Bergen,  the  shells  were  almost 
flinty  hard,  and  the  flesh,  even  when  thick  and 
tender,  was  bitter.  Some  of  the  fruits  looked  so 
much  like  the  Bergen  that  I  was  led  to  think  that 
the  gourd  had  largely  disappeared.  The  very  hard 
but  thin  paper-like  shell  which  the  gourd  had  laid 
over  the  thick  yellow  flesh  of  the  Bergen,  I 
thought  might  serve  a  useful  purpose,  and  make 
the  squash  a  better  keeper.  And  I  found  that  it 
was  a  great  protection,  for  the  squash  could  stand 
any  amount  of  rough  handling,  and  was  even  not 
injured  by  ten  degrees  of  frost.  All  this  was  an 
acquisition,  and,  as  the  squash  was  handsome  and 
exceedingly  productive,  nothing  more  seemed  to 
be  desired.  But  it  still  remained  to  have  a  squash 
for  dinner.  The  cook  complained  of  the  hard 
shell,  but,  once  inside,  the  flesh  was  thick  and 
attractive,  and  it  cooked  nicely.  But  the  flavor ! 
Dregs  of  quinine,  gall,  and  boneset!  The  gourd 
was  still  there  ! 

VI.  Uncertainties  of  Pollination. 

We  have  now  seen  that  uncertainty  follows 
hybridization,  and,  in  closing,  I  will  say  that 
uncertainty  also  attaches  to  the  mere  act  of 
pollination.      Between   some    species    which    are 


84  PHILOSOPHY   OF   CBOSSING    PLANTS. 

closely  allied  and  which  have  large  and  strong 
flowers,  four-fifths  of  the  attempts  towards  cross- 
pollination  may  be  successful ;  but  such  a  large 
proportion  of  successes  is  not  common,  and  it 
may  be  infrequent  even  in  pollinations  between 
plants  of  the  same  species  or  variety.  Some  of 
the  failure  is  due  in  many  cases  to  unskilful  opera- 
tion, but  even  the  most  expert  operators  fail  as 
often  as  they  succeed  in  promiscuous  pollinating. 
There  is  good  reason  to  believe,  as  Darwin  has 
shown,  that  the  failure  may  be  due  to  some  selec- 
tive power  of  individual  plants,  by  which  they  re- 
fuse pollen  which  is,  in  many  instances,  acceptable 
to  other  plants  even  of  the  same  variety  or  stock. 
The  lesson  to  be  drawn  from  these  facts  is  that 
operations  should  be  as  many  as  possible,  and  that 
discouragement  should  not  come  from  failure. 
In  order  to  illustrate  the  varying  fortunes  of  the 
pollinator,  I  will  transcribe  some  notes  from  my 
field-book. 

Two  hundred  and  thirty-four  pollinations  of 
gourds,  pumpkins,  and  squashes,  mostly  between 
varieties  of  one  species  (Cucurbita  Pepo),  and  in- 
cluding some  individual  pollinations,  gave  one 
hundred  and  seventeen  failures  and  one  hundred 
and  seventeen  successes.  These  crosses  were  made 
in  varying  weather,  from  July  28  to  August  30. 
In  some  periods  nearly  all  the  operations  would 
succeed,  and  at  other  times  most  of  them  would 


RECORDS    OF   POLLINATIONS.  85 

fail.  I  have  always  regarded  these  experiments  as 
among  my  most  successful  ones,  and  yet  but  half 
of  the  pollinations  "  took."  But  one  must  not 
understand  that  I  actually  secured  seeds  from  even 
all  these  one  hundred  and  seventeen  fruits,  for 
some  of  them  turned  out  to  be  seedless,  and  some 
were  destroyed  by  insects  before  they  were  ripe,  or 
they  were  lost  by  accidental  means.  A  few  more 
than  half  of  the  successful  pollinations  —  if  by  suc- 
cess we  mean  the  formation  and  growth  of  fruit  — 
really  secured  us  seeds,  or  about  one-fourth  of  the 
whole  number  of  efforts. 

Twenty  pollinations  were  made  between  potato 
flowers,  and  they  all  failed ;  also,  seven  pollinations 
of  red  peppers,  four  of  husk-tomato,  two  of  Nico- 
tian a  affinis  upon  petunia  and  two  of  the  reciprocal 
cross,  twelve  of  radish,  one  of  Mirabilis  Jalapa  upon 
M.  longiflora  and  two  of  the  reciprocal  cross,  three 
Convolvulus  major  upon  C.  minor  and  one  of  the 
reciprocal,  one  muskmelon  by  squash,  two  musk- 
melons  by  watermelon,  and  one  muskmelon  by 
cucumber. 

This  is  but  one  record.  Let  me  give  another :  — 
Cucumber,  ninety-five  efforts:  fifty-two  suc- 
cesses, forty-three  failures.  Tomato,  forty-three 
efforts:  nineteen  successes,  twenty-four  failures. 
Egg-plant,  seven  efforts  :  one  success,  six  failures. 
Pepper,  fifteen  efforts :  one  success,  fourteen  fail- 
ures.      Husk-tomato,  forty-five   efforts:    forty-five 


86  PHILOSOPHY   OF   CROSSING   PLANTS. 

failures.  Pepino,  twelve  efforts:  twelve  failures. 
Petunia  by  Nicotiana  affinis,  eleven  efforts  :  eleven 
failures.  Nicotiana  affinis  by  petunia,  six  efforts : 
six  failures.  General  Grant  tobacco  by  Nicotiana 
affinis,  eleven  efforts  :  eight  successes,  three  fail- 
ures. Nicotiana  affinis  by  General  Grant  tobacco, 
fifteen  efforts :  fifteen  failures.  General  Grant 
tobacco  by  General  Grant  tobacco,  one  effort :  one 
success.  Nicotiana  affinis  by  Nicotiana  affinis,  three 
efforts :  two  successes,  one  failure.  Tuberous  be- 
gonia, five  efforts  :  five  successes. 

Total,  three  hundred  and  twelve  efforts  :  eighty- 
nine  successes,  two  hundred  and  twenty-three 
failures. 

Conclusion. 

And  now,  the  sum  of  it  all  is  this :  encourage  in 
every  way  crosses  within  the  limits  of  the  variety 
and  in  connection  with  change  of  stock,  expecting 
increase  in  vigor  and  productiveness ;  hybridize 
if  you  wish  to  experiment,  but  do  it  carefully, 
systematically,  thoroughly,  and  do  not  expect  too 
much.  Extend  Darwin's  famous  proposition  to 
read:  Nature  abhors  both  perpetual  self-fertiliza- 
tion and  hybridization. 


LECTURE   III. 

HOW   DOMESTIC   VARIETIES   ORIGINATE. 

"  The  key  is  man's  power  of  accumulative 
selection  :  nature  gives  successive  variations ; 
man  adds  them  up  in  certain  directions  useful 
to  him."  This,  in  Darwin's  phrase,  is  the  essence 
of  the  cultivator's  skill  in  ameliorating  the  vege- 
table kingdom.  So  far  as  man  is  concerned,  the 
origin  of  the  initial  variation  is  largely  chance, 
but  this  start  or  variation  once  given,  he  has  the 
power,  in  most  cases,  to  perpetuate  it  and  to 
modify  its  characters.  There  are,  then,  two  very 
different  factors  or  problems  in  the  origination  of 
garden  varieties,  —  the  production  of  the  first  de- 
parture or  variation,  and  the  subsequent  breeding 
of  it.  Persons  who  give  little  thought  to  the  sub- 
ject, look  upon  variation  as  the  end  of  their  endeav- 
ors, thinking  that  a  form  comes  into  being  with  all 
its  characters  well  marked  and  fixed.  In  reality, 
however,  variation  is  but  the  beginning  ;  selection 
is  the  end. 

I.    Indeterminate  Varieties. 

There  are  two  general  classes  of  garden  varie- 
ties  as   respects   the   method   of   their  origin,  — 

87 


88        HOW   DOMESTIC    VARIETIES   ORIGINATE. 

those  which  come  into  existence  somewhat  sud- 
denly and  which  require  little  else  of  the  hus- 
bandman than  the  multiplication  of  them,  and 
those  which  are  the  result  of  a  slow  evolution  or 
direct  breeding.  The  former  are  indeterminate 
or  uncertain,  and  the  latter  are  determinate  or 
definite.  The  greater  part  of  those  in  the  first 
class  are  plants  which  are  multiplied  or  divided 
by  bud-propagation.  They  comprise  nearly  all 
our  fruits,  the  woody  ornamental  plants,  and  such 
herbaceous  genera  as  begonia,  canna,  gladiolus, 
lily,  dahlia,  carnation,  chrysanthemum,  and  the 
like,  —  in  fact,  all  those  multiplied  by  grafting, 
cuttings,  bulbs,  or  other  asexual  parts.  The 
original  plant  may  be  either  a  seedling  or  a  bud- 
sport.  The  gardener,  who  is  always  on  the  look- 
out for  novelties,  discovers  its  good  qualities  and 
propagates  it. 

Varieties  which  are  habitually  multiplied  by 
buds,  as  in  those  plants  which  I  have  mentioned 
in  the  last  paragraph,  vary  widely  when  grown 
from  seeds,  so  that  every  seedling  may  be 
markedly  distinct.  As  soon,  however,  as  varie- 
ties are  widely  and  exclusively  propagated  by 
seeds,  they  develop  a  capacity  of  carrying  the 
greater  part  of  the  individual  differences  down 
to  the  offspring.  That  is,  seedlings  from  bud- 
multiplied  plants  do  not  "  come  true,"  as  a  rule, 
whilst    those    from    seed  -  propagated    plants    do 


INDETERMINATE    VARIETIES.  89 

" come  true."  The  reason  of  this  difference  will 
become  apparent  upon  a  moment's  reflection.  In 
the  seed-propagatecl  plants,  like  the  kitchen-gar- 
den vegetables  and  the  annual  flowers,  we  select 
the  seeds  and  thereby  eliminate  all  those  varia- 
tions which  would  have  arisen  had  the  discarded 
seeds  been  sown.  In  other  words,  we  are  con- 
stantly fixing  the  tendency  to  "come  true,"  for 
this  feature  of  plants  is  as  much  a  variation  as 
form  or  color  or  any  other  attribute  is.  Suppose, 
for  instance,  that  a  certain  variation  were  to  re- 
ceive two  opposite  treatments,  the  seeds  from  one- 
half  of  the  progeny  being  carefully  selected  year 
by  year,  and  all  those  from  untypical  plants  dis- 
carded, whilst  in  the  other  half  all  the  seeds  from 
all  the  plants,  whether  good  or  bad,  are  saved 
and  sown.  In  the  one  case,  it  will  be  seen,  we 
are  fixing  the  tendency  to  "  come  true,"  for  this 
is  all  that  constitutes  a  horticultural  variety,  — 
a  brood  which  is  very  much  like  all  its  parents. 
In  the  other  case,  we  are  constantly  eliminating 
the  tendency  to  "  come  true  "  by  allowing  every 
modifying  agency  full  sway.  So  the  very  act  of 
taking  seeds  only  from  plants  which  have  "  come 
true,"  tends  to  still  more  strongly  fix  the  heredi- 
tary force  within  narrow  limits.  Working  against 
this  restrictive  force,  however,  are  all  the  agencies 
of  environment,  so  that,  fortunately,  now  and 
then  a  seed  gives  a  "  rogue,"  or  a  plant  widely 


90        HOW   DOMESTIC    VARIETIES    ORIGINATE. 

unlike  its  parent,  and  this  may  be  the  start  for  a 
new  variety. 

With  bud-multiplied  varieties,  however,  the 
case  is  very  different.  Here  every  seed  may  be 
sown,  as  in  the  illustrative  case  above,  because 
the  seedlings  are  not  wanted  for  themselves,  but 
simply  as  stocks  upon  which  to  bud  or  graft  the 
desired  varieties.  So  there  is  no  seed  selection  in 
the  ordinary  propagation  of  apples,  pears,  peaches, 
and  the  other  orchard  fruits.  The  seeds  are  taken 
indiscriminately  from  pomace  or  the  refuse  of  can- 
ning and  evaporating  factories.  But  every  annual 
garden  vegetable  is  always  grown  from  seeds  more 
or  less  carefully  saved  from  plants  which  possess 
some  desired  attribute.  There  is  no  reason  why 
the  tree  fruits  should  not  reproduce  themselves 
from  seeds  just  as  closely  as  the  annual  herbs  do,  if 
they  were  to  be  as  carefully  propagated  by  selected 
seeds  through  a  long  course  of  generations.  There 
is  excellent  proof  of  this  in  the  well-marked  races 
or  families  of  Russian  apples.  In  that  country, 
grafting  has  been  little  employed,  and  conse- 
quently it  has  been  necessary  to  select  seeds 
only  from  acceptable  trees  in  order  that  the  off- 
spring might  be  more  acceptable.  So  the  Russian 
apples  have  come  to  run  in  groups  or  families,  each 
family  bearing  the  mark  of  some  strong  ancestor. 
Most  of  the  seedlings  of  the  Duchess  of  Olden- 
burg are  recognizable  because  of  their  likeness  to 


PLANT-BREEDING.  91 

the  parent.  We  may  thus  trace  an  incipient  ten- 
dency in  our  own  fruits  towards  racial  characters. 
The  Fameuse  type  of  apples,  for  example,  tends  to 
perpetuate  itself  ;  and  a  similar  tendency  is  very 
well  marked  in  the  Damson  and  Green  Gage 
plums,  the  Orange  quince,  Concord  grape,  and 
Hill's  Chili  and  Crawford  peaches.  But  inas- 
much as  bud-multiplication  is  so  essential  in 
nursery  practice,  we  can  hardly  hope  for  the 
time  when  our  trees  and  shrubs,  or  even  our  per- 
ennial herbs,  will  u come  true"  with  much  cer- 
tainty. In  them,  therefore,  we  get  new  varieties 
by  simply  sowing  the  seeds  ;  but  in  seed-propa- 
gated varieties  we  must  depend  either  upon  chance 
variations  or  else  we  must  resort  to  definite  plant- 
breeding. 

II.   Plant-breeding. 

The  breeding  of  domestic  animals  is  attended, 
for  the  most  part,  with  such  definite  and  often 
precise  results  that  there  has  come  to  be  a  gen- 
eral desire  to  extend  the  same  principles  to 
plants.  It  is  not  unusual  to  hear  well-informed 
people  say  that  it  is  possible  to  breed  plants  with 
as  much  certainty  and  exactness  as  it  is  to  breed 
animals.  The  fact  is,  however,  that  such  exact- 
ness will  never  be  possible,  because  plants  are 
very  unlike  animals  in  organization,  and  because, 


92       HOW    DOMESTIC    VARIETIES   ORIGINATE. 

also,  the  objects  sought  in  the  two  cases  are  fun- 
damentally unlike.  Plants,  as  we  have  seen,  are 
made  up  of  a  colony  of  potential  individuals,  and 
to  breed  between  two  plants  by  crossing  means 
that  we  must  choose  the  sex-parents  from  amongst 
as  many  individuals  as  there  are  flowers  or  branches 
on  the  two  plants,  whilst  in  animals  we  choose  two 
definite  personal  parents.  And  these  personal 
parents  are  either  male  or  female,  and  the  union 
is  essential  to  the  production  of  offspring,  whilst 
in  plants  each  parent  —  that  is,  each  flower  —  is 
generally  both  male  and  female,  and  the  union  of 
two  is  not  essential  to  the  production  of  offspring, 
for  the  plant  is  capable  of  multiplying  itself  by 
buds.  The  element  of  chance,  therefore,  is  one 
hundred,  or  more,  to  one  in  crossing  plants  as 
compared  with  crossing  animals.  Then,  again, 
the  plant-parents  are  modified  profoundly  by  every 
environmental  condition  of  soil  and  temperature 
and  sunshine,  or  other  external  condition,  since 
they  possess  no  bodily  temperature,  no  choice  of 
conditions,  and  no  volition  to  enable  them  to 
overcome  the  circumstances  in  which  they  are 
placed.  Animals,  on  the  contrary,  have  all  these 
elements  of  personality,  and  the  breeder  is  also 
able  to  control  the  conditions  of  their  lives  to  a 
nicety.  In  view  of  all  these  facts,  it  is  not  strange 
that  animals  can  be  bred  by  crossing  with  more 
confidence  than  plants  can.     But  there  is  another 


ANIMALS   AND   PLANTS.  V6 

and  even  more  important  difference  between  the 
breeding  of  animals  and  the  breeding  of  plants. 
In  animals,  our  sole  object  is  to  secure  simply  one 
animal  or  one  brood  of  offspring.  In  plants,  our 
object  is,  in  general,  to  secure  a  race  or  genera- 
tions of  offspring,  which  may  be  disseminated 
freely  over  the  earth.  In  the  bovine  race,  for 
example,  our  object  in  breeding  is  to  produce  one 
cow  with  given  characters  ;  in  turnips,  our  object 
is  to  produce  a  new  variety,  the  seed  of  which 
will  reproduce  the  variety,  whether  sown  in  Penn- 
sylvania or  Ceylon.  It  is  apparent,  therefore,  that 
any  comparisons  drawn  between  the  breeding  of 
animals  and  plants  are  fundamentally  fallacious. 

Is  there,  then,  any  such  thing  as  plant-breeding, 
any  possibility  that  the  operator  can  proceed  Avith 
some  confidence  that  he  may  obtain  the  ideal 
which  he  has  in  mind?     Yes,  to  a  certain  extent. 

It  is  apparent  that  the  very  first  effort  on  the 
part  of  the  plant-breeder  must  be  to  secure  indi- 
vidual differences ;  for  so  long  as  the  plants  which 
he  handles  are  very  closely  alike,  so  long  there 
will  be  little  hope  of  obtaining  new  varieties.  He 
must,  therefore,  cause  his  plants  to  vary.  In 
plants  which  are  comparatively  unvariable,  it  is 
frequently  impossible  to  produce  variations  in  the 
desired  direction  at  once,  but  it  is  more  important 
to  "  break  "  the  type,  —  that  is,  to  make  it  depart 
markedly  from    its    normal    behavior    in   any   or 


94        HOW   DOMESTIC    VARIETIES    ORIGINATE. 

many  directions  (page  19).  If  the  type  once 
begins  to  vary,  to  break  up  into  different  forms, 
the  operator  may  be  sure  that  it  will  soon  become 
plastic  enough  to  allow  of  modification  in  the 
manner  which  he  desires.  But  whilst  it  is  im- 
portant or  even  necessary  to  break  a  well-marked 
type  into  many  forms,  it  would  no  doubt  be  un- 
wise to  encourage  this  tendency  after  it  once 
appears,  lest  the  plant  acquire  a  too  strong  habit 
of  scattering.  This  initial  variation  is  induced 
by  changing  the  conditions  in  which  the  plant  has 
habitually  grown,  as  a  change  of  seed,  change  of 
soil,  tillage,  varying  the  food  supply,  crossing-  and 
the  like. 

As  a  matter  of  fact,  however,  nearly  all  plants 
which  have  been  long  cultivated  are  already  suf- 
ficiently variable  to  afford  a  starting-point  for 
breeding.  The  operator  should  have  a  vivid 
mental  picture  of  the  variety  which  he  designs  to 
obtain  ;  then  he  should  select  that  plant  in  his 
plantation  which  is  the  nearest  his  ideal,  and  sow 
the  seeds  of  it.  From  the  seedlings  he  should 
again  select  the  individuals  which  most  nearly 
approach  his  type,  and  so  on,  generation  after 
generation,  until  the  desired  object  is  attained. 
It  is  important,  if  he  is  to  make  rapid  progress, 
that  he  keep  the  same  ideal  in  mind  year  by  year, 
otherwise  there  will  be  vacillation  and  the  prog- 
ress of    one    year  may  be   undone  by  a  counter 


ANTAGONISTIC    FEATURES.  95 

movement  the  following  year.  In  this  way,  it 
will  be  found  that  almost  any  character  of  a  plant 
may  be  either  intensified  or  lessened.  This  is 
man's  nearest  approach  to  the  Creator  in  his 
dominion  over  the  physical  forms  of  life,  and  it 
is  great  and  potent  in  proportion  as  it  sets  for 
itself  correct  ideals  in  the  beginning  and  adheres 
to  them  until  the  end. 

When  beginning  this  selection  or  breeding  for 
an  ideal,  it  is  important  that  impossible  or  contra- 
dictory results  should  be  avoided.  Some  of  the 
cautions  and  suggestions  which  need  to  be  con- 
sidered are  these  :  — 

1.  Avoid  striving  after  features  which  are  antag- 
onistic or  foreign  to  the  species  or  genus  with  which 
you  are  working.  Every  group  of  plants  has  be- 
come endowed  with  certain  characters  or  lines 
of  development,  and  the  cultivator  will  secure 
quicker  and  surer  results  if  he  works  along  the 
same  lines,  rather  than  to  attempt  to  thwart  them. 
Nature  gives  the  hint  :  let  men  follow  it  out, 
rather  than  to  endeavor  to  create  new  types  of 
characters.  Let  us  take  some  of  the  solanaceous 
plants  as  examples.  There  are  certain  types  of 
the  genus  solanum  which  have  a  natural  habit  of 
tuber-bearing,  as  the  potato.  Such  species  should 
be  bred  for  tubers  and  not  for  fruits.  There  are 
other  solanums,  however,  like  the  egg-plants  and 
the  pepinoes,  which  naturally  vary  or  develop  in 


96        HOW   DOMESTIC    VARIETIES    ORIGINATE. 

the  direction  of  fruit-bearing,  and  these  should  be 
bred  for  fruits  and  not  for  tubers  ;  and  the  same 
should  be  true  in  the  related  genera  of  tomatoes, 
red  peppers,  and  physalis.  Those  ambitious  per- 
sons who  are  always  looking  for  a  tuber-bearing 
tomato,  therefore,  might  better  concentrate  their 
energies  on  the  potato,  for  the  tomato  is  not  devel- 
oping in  that  direction ;  and  even  if  the  tomato 
could  be  made  to  produce  tubers,  it  would  thereby 
lessen  its  fruit  production,  for  plants  cannot  main- 
tain two  diverse  and  profitable  crops  at  the  same 
time.  It  is  more  reasonable,  and  certainly  more 
practicable,  to  grow  potatoes  on  potato  plants  and 
tomatoes  on  tomato  plants. 

2.  The  quickest  and  most  marked  results  are  to 
be  expected  in  those  groups  or  species  ivhich  are  nor- 
mally the  most  variable.  There  are  a  greater  num- 
ber of  variations  or  starting-points  in  such  species ; 
but  it  also  follows  that  the  forms  are  less  stable 
the  more  the  species  is  variable.  Yet  the  varia- 
tions, being  very  plastic,  yield  themselves  readily 
to  the  wishes  of  the  operator.  Carriere  puts  the 
thought  in  this  form  :  "  The  stability  of  forms,  in 
any  group  of  plants,  is,  in  general,  in  inverse  ratio 
to  the  number  of  the  species  which  it  contains, 
and  also  to  the  degree  of  its  domestication." 

The  most  variable  types  are  the  most  dominant 
ones  over  the  earth  ;  that  is,  they  occur  in  greater 
numbers  and  Tinder  more  diverse  conditions  than 


VARIABLE   TYPES.  97 

the  comparatively  invariable  t}^pes  do.  The  corn- 
posits,  or  sunflower-like  plants,  comprise  a  ninth 
or  tenth  of  the  total  species  of  flowering  plants, 
and  the  larger  part  of  the  subordinate  types  or 
genera  contain  many  forms  or  species.  Aster, 
goldenrod,  the  hawkweeds,  thistles,  and  other 
groups,  are  representative  of  the  cosmopolitan  or 
variable  types  of  composites.  Whenever,  for  any 
reason,  any  type  begins  to  decline  in  variability, 
it  also  begins  to  perish  ;  it  is  then  tending  towards 
extinction.  Monotypic  genera  —  those  which  con- 
tain but  a  single  species  —  are  generally  of  local 
or  disconnected  distribution,  and  are,  for  the  most 
part,  vanishing  remnants  of  a  once  dominant  or 
important  t}rpe.  As  a  rule,  most  of  our  widely 
variable  and  staple  cultivated  species  are  mem- 
bers of  large,  or  at  least  polytypic  genera.  Such, 
for  example,  are  the  apples  and  pears,  peaches 
and  plums,  oranges  and  lemons,  roses,  bananas, 
chrysanthemums,  pinks,  cucurbits,  beans,  potato, 
grapes,  barley,  rice,  cotton.  A  marked  exception 
to  this  statement  is  maize,  which  is  immensely 
variable  and  is  generally  held  to  have  come  from 
a  single  species  ;  but  the  genesis  of  maize  is  un- 
known, and  it  is  possible,  though  scarcely  proba- 
ble, that  more  than  one  species  is  concerned  in  it. 
Wheat  is  also  a  partial  exception,  although  the 
original  specific  type  is  not  understood ;  and  the 
latest  monographers  admit  three  or  four  other  spe- 


98        HOW   DOMESTIC    VARIETIES    ORIGINATE. 

cies  to  the  genus,  aside  from  wheat.  There  are 
other  exceptions,  but  they  are  mostly  unimportant, 
and,  in  the  main,  it  may  be  said  that  the  domi- 
nant domestic  types  of  plants  represent  markedly 
polytypic  genera. 

3.  Breed  for  one  tiling  at  a  time.  The  person 
who  strives  at  the  same  time  for  increase  or  modi- 
fication in  prolificacy  and  flavor  will  be  likely  to 
fail  in  both.  He  should  work  for  one  object 
alone,  simply  giving  sufficient  attention  to  sub- 
sidiary objects  to  keep  them  up  to  normal  stand- 
ard. This  is  really  equivalent  to  saying  that 
there  can  be  no  such  thing  as  the  perfect  all- 
around  variety  which  so  many  people  covet.  Va- 
rieties must  be  adapted  to  specific  uses,  —  one  for 
shipping,  one  for  canning,  one  for  dessert,  one  for 
keeping  qualities,  and  the  like.  The  more  good 
varieties  there  are  of  any  species,  the  more  Avidely 
and  successfully  that  species  can  be  cultivated. 

4.  Bo  not  desire  contradictory  attributes  in  any 
variety.  A  variety,  for  example,  which  bears  the 
maximum  number  of  fruits  or  flowers  cannot  be 
expected  to  greatly  increase  the  size  of  those 
organs  without  loss  in  numbers.  This  is  well 
shown  in  the  tomato.  The  original  tomato  pro- 
duced from  six  to  ten  fruits  in  a  cluster,  but  as 
the  fruits  increased  in  size  the  numbers  in  each 
cluster  fell  to  two  or  three.  That  is,  increase  in 
size  proceeded  somewhat  at  the  expense  of  n inner- 


SELECT   FOR    THE   ENTIRE   PLANT.  \)\) 

ical  productivity ;  yet  the  total  weight  of  fruit 
per  plant  has  greatly  increased.  The  same  is 
true  of  apples  and  pears ;  for  whilst  these  trees 
bear  flowers  in  clusters,  they  generally  bear  their 
fruits  singly.  Originally,  every  flower  normally 
set  fruit.  The  reason  why  blackberries,  currants, 
and  grapes  do  not  increase  more  markedly  in  size, 
is  probably  because  the  size  of  cluster  has  been 
given  greater  attention  than  the  size  of  berry. 
Plants  which  now  bear  a  full  crop  of  tubers 
cannot  be  expected  to  increase  greatly  in  fruit- 
bearing,  as  I  have  already  explained  under 
Rule  1.  This  fact  is  illustrated  in  the  potato, 
in  which,  as  tuber  production  has  increased,  seed 
production  has  decreased,  so  that  potato  growers 
now  complain  that  potatoes  do  not  produce  bolls 
as  freely  as  they  did  years  ago. 

5.  When  selecting  seeds,  remember  that  the  char- 
acter of  the  whole  plant  is  more  imjjortant  than  the 
character  of  any  one  branch  or  part  of  the  plant ; 
and  the  more  uniform  the  'plant  in  all  its  parts,  the 
greater  is  the  likelihood  that  it  will  transmit  its 
characters.  If  one  is  striving  for  larger  flowers, 
for  instance,  he  will  secure  better  results  if  he 
choose  seeds  from  plants  which  bear  large  flowers 
throughout,  than  he  will  if  he  choose  them  from 
some  one  large-flowering  branch  on  a  plant  which 
bears  indifferent  flowers  on  the  remaining  branches, 
even  though  this  given  branch  produce  much  larger 


100      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

flowers  than  those  borne  on  the  large -flowered 
plant.  Small  potatoes  from  productive  hills  give 
a  better  product  than  large  potatoes  from  unpro- 
ductive hills.  The  practice  of  selecting  large 
ears  from  a  bin  of  corn,  or  large  melons  from  the 
grocer's  wagon,  is  much  less  efficient  in  produc- 
ing large  products  the  following  season  than  the 
practice  of  going  into  the  fields  and  selecting  the 
most  uniformly  large-fruited  parents  would  be. 
A  very  poor  plant  may  occasionally  produce  one 
or  two  very  superior  fruits,  but  the  seeds  are 
more  likely  to  perpetuate  the  characters  of  the 
plant  than  of  the  fruits. 

The  following  experiences  detailed  by  Henri  L. 
de  Vilmorin  illustrate  my  proposition  admirably: 
"  I  tried  an  experiment  with  seeds  of  Chrysanthe- 
mum carinatum  gathered  on  double,  single,  and 
semi-double  heads,  all  growing  on  one  plant, 
and  found  no  difference  whatever  in  the  propor- 
tion of  single  and  double-flowered  plants.  In 
striped  verbenas,  an  unequal  distribution  of  the 
color  is  often  noticed ;  some  heads  are  pure  white, 
some  of  a  self  color,  and  most  are  marked  with 
colored  stripes  on  white  ground.  I  had  seeds 
taken  severally  from  all  and  tested  alongside 
one  another.  The  result  was  the  same.  All  the 
seeds  from  one  plant,  whatever  the  color  of  the 
flower  that  bore  them,  gave  the  same  proportion 
of  plain  and  variegated  flowers." 


UNIFORMNESS    IN   THE   PARTS.  101 

The  second  part  of  my  proposition  is  equally  as 
important  as  the  first,  —  the  fact  that  a  plant 
which  is  uniform  in  all  its  branches  or  parts  is 
more  likely  to  transmit  its  general  features  than 
one  which  varies  within  itself.  It  is  well  known 
that  bean  plants  often  produce  beans  with  various 
styles  of  markings  on  the  same  plant  or  even  in 
the  same  pod,  yet  these  variations  rarely  ever 
perpetuate  themselves.  The  same  remark  may 
be  applied  to  variations  in  peas.  These  illustra- 
tions only  add  emphasis  to  the  fact  that  intending 
plant-breeders  should  give  greater  heed  than  they 
usually  do  to  the  entire  plant,  rather  than  confine 
their  attention  to  the  particular  part  or  organ 
which  they  desire  to  improve. 

At  first  thought,  it  may  look  as  if  these  facts 
are  directly  opposed  to  the  proposition  which  I 
emphasized  in  my  first  lecture,  that  every  branch 
of  a  plant  is  a  potential  autonomy,  but  it  is  really 
a  confirmation  of  it.  The  variation  itself  shows 
that  the  branch  is  measurably  independent,  but  it 
is  not  until  the  conditions  or  causes  of  the  vari- 
ation are  powerful  enough  to  affect  the  entire 
plant  that  they  are  sufficiently  impressed  upon 
the  organization  of  the  plant  to  make  their  effects 
hereditary. 

There  is  an  apparent  exception  to  the  law  that 
the  character  of  the  entire  plant  is  more  impor- 
tant than  any  one  organ  or  part  of  it,  in  the  case 


102      HOW    DOMESTIC    VARIETIES   ORIGINATE. 

of  the  seeds  themselves.  That  is,  better  results 
usually  follow  the  sowing  of  large  and  heavy 
seeds  than  of  small  or  unselected  seeds  from  the 
same  plant.  This,  however,  does  not  affect  the 
main  proposition,  for  the  seed  is  in  a  measure 
independent  of  the  plant-body,  and  is  not  so 
directly  influenced  by  environment  as  the  other 
organs  are.  And,  again,  the  seed  receives  a  part 
of  its  elements  from  a  second  or  male  parent. 
The  good  results  which  follow  the  use  of  large 
seeds  are,  chiefly,  greater  uniformity  of  crop, 
increased  vigor,  often  a  gain  in  earliness  and 
sometimes  in  bulk,  and  generally  a  greater  ca- 
pacity for  the  production  of  seeds.  These  results 
are  probably  associated  less  with  any  innate  he- 
reditable  tendencies  than  with  the  mere  vegeta- 
tive strength  and  uniformness  of  the  large  seeds. 
The  large  seeds  usually  germinate  more  quickly 
than  the  small  ones,  provided  both  are  equally 
mature,  and  they  push  the  plantlet  on  more 
vigorously.  This  initial  gain,  coming  at  the 
most  critical  time  in  the  life  of  the  new  indi- 
vidual, is  no  doubt  responsible  for  very  much  of 
the  result  which  follows.  The  uniformity  of  crop 
is  the  most  important  advantage  which  comes  of 
the  use  of  large  seeds,  and  this  is  obviously  the 
result  of  the  elimination  of  all  seeds  of  varying 
degrees  of  maturity,  of  incomplete  growth  and 
formation,  and  of  low  vitality. 


PROGENY   OF   IMMATURE   SEEDS  103 

Another  important  consideration  touching  the 
selection  of  seeds  is  the  fact  that  very  immature 
seeds  give  a  feeble  but  precocious  progeny.  This 
has  long  been  observed  by  gardeners,  but  Sturte- 
vant,  Arthur,  and  Goff  have  recently  made  a 
critical  examination  of  the  subject.  "  It  is  not 
the  slightly  unripe  seeds  that  give  a  noticeable 
increase  in  earliness,"  according  to  Arthur,  "  but 
very  unripe  seeds,  gathered  from  fruit  [tomatoes] 
scarcely  of  full  size  and  still  very  green.  Such 
seeds  do  not  weigh  more  than  two-thirds  as  much 
as  those  fully  ripe.  They  germinate  readily,  but 
the  plantlets  lack  constitutional  vigor  and  are 
more  easily  affected  by  retarding  or  harmful 
influences.  If  they  can  be  brought  through  the 
early  period  of  growth  and  become  well  estab- 
lished, and  the  foliage  or  fruit  is  not  attacked  by 
rots  or  blights,  the  grower  will  usually  be  re- 
warded by  an  earlier  and  more  abundant  crop  of 
slightly  smaller  and  less  firm  fruit.  These  char- 
acters will  be  more  strongly  emphasized  in  sub- 
sequent years  by  continuous  seed  propagation." 
Goff  remarks  that  the  increase  in  earliness  in 
tomatoes,  following  the  use  of  markedly  immature 
seeds,  "is  accompanied  by  a  marked  decrease  in 
the  vigor  of  the  plant,  and  in  the  size,  firmness, 
and  keeping  quality  of  the  fruit."  These  results 
are  probably  closely  associated  with  the  chemical 
constitution  and  content  of  the  immature  seeds. 


104      HOAV   DOMESTIC    VARIETIES    ORIGINATE. 

The  organic  compounds  have  probably  not  yet 
reached  a  state  of  stability,  and  they  therefore 
respond  quickly  to  external  stimuli  when  placed 
in  conditions  suitable  to  germination ;  and  there 
is  little  food  for  the  nourishment  of  the  plantlet. 
The  consequent  weakness  of  the  plantlet  results 
in  a  loss  of  vegetative  vigor,  which  is  earliness 
(see  Rule  11). 

Still  another  feature  connected  with  the  choice 
of  seeds  is  the  fact  that  in  some  plants,  as  in  some 
Ipomoeas,  for  example,  the  color  of  the  seed  is 
more  or  less  intimately  associated  with  the  color 
of  the  flower  which  produced  them  and  also  with 
the  color  of  the  flowers  which  they  will  produce. 

6.  Plants  which  have  any  desired  characteristics 
in  common  may  differ  widely  in  their  ability  to 
transmit  these  characters.  It  is  generally  impos- 
sible for  the  cultivator  to  determine,  from  the 
appearance  of  any  given  number  of  similar  plants, 
which  of  them  Avill  give  progeny  the  most  unvari- 
able  and  the  most  like  its  parent ;  but  it  may  be 
said  that  those  individuals  which  grow  in  the  most 
usual  or  normal  environments  are  most  likely  to 
perpetuate  themselves.  A  very  unusual  condi- 
tion, as  of  soil,  moisture,  or  exposure,  is  not  easily 
imitated  when  providing  for  the  succeeding  gen- 
eration, and  a  return  to  normal  conditions  of  envi- 
ronment may  be  expected  to  be  followed  by  a  more 
or  less  complete  return  to  normal  attributes  on  the 


SELECT   SEVERAL   STARTING-POINTS.         105 

part  of  the  plant.  If  the  same  variation,  there- 
fore, were  to  occur  in  plants  growing  under  widely 
different  conditions,  the  operator  who  wishes  to 
preserve  the  new  form  should  take  particular  care 
to  select  his  seeds  from  those  individuals  which 
seem  to  have  been  least  influenced  by  the  imme- 
diate conditions  in  which  they  have  grown. 

Again,  if  the  same  variation  appears  both  in 
uncrossed  and  crossed  plants,  the  best  results 
should  be  expected  in  selecting  seeds  from  the 
former.  We  have  already  seen,  in  the  second 
lecture,  how  it  is  that  crosses  are  unstable,  and 
how  the  instability  is  apt  to  be  the  greater  the 
more  violent  the  cross.  "  Cross-breeding  greatly 
increases  the  chance  of  wide  variation,"  writes 
Henri  L.  de  Vilmorin,  "  but  it  makes  the  task  of 
fixation  more  difficult." 

It  is  very  important,  therefore,  when  selecting 
seeds  from  plants  which  seem  to  give  promise  of 
a  new  variety,  to  sow  the  seeds  of  each  plant 
separately,  and  then  make  the  subsequent  selec- 
tions from  the  most  stable  generation;  and  it  is 
equally  important  that  the  operator  should  not 
trust  to  a  single  plant  as  a  starting-point,  when- 
ever he  has  several  promising  plants  from  which 
to  choose. 

7.  The  less  marked  the  departure  from  the 
genius  of  the  normal  type,  the  greater,  in  general, 
is  the  likelihood  that  it  will  be  perpetuated.     That 


106      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

is,  widely  aberrant  forms  are  generally  unstable. 
This  is  admirably  illustrated  in  crosses.  The 
seed-progeny  of  crosses  between  closely  related 
varieties,  or  between  different  plants  of  the  same 
variety,  is  more  uniform  and  generally  more  easy 
of  improvement  by  selection  than  the  progeny  of 
hybrids.  In  uncrossed  plants,  the  general  ten- 
dency is  to  resemble  their  parents,  and  the  greater 
the  number  of  like  ancestors,  the  greater  is  the  ten- 
dency to  "come  true."  There  is  thought  to  be  a 
tendency,  though  necessarily  a  weak  one,  to  return 
to  some  particular  ancestor,  or  to  "date  back." 
This  is  known  as  atavism.  The  so-called  atavistic 
forms  are  likely  to  be  unstable,  to  break  up  into  nu- 
merous forms,  or  to  return  more  or  less  completely 
to  the  type  of  the  main  line  of  the  ancestry.  The 
following  statements  touching  some  of  the  rela- 
tions of  atavism  to  the  amelioration  of  plants,  are 
the  results  of  an  excellent  study  of  heredity  in 
lupines  by  Louis  Leveque  de  Vilmorin  :  — 

"1.  The  tendency  to  resemble  its  parents  is 
generally  the  strongest  tendency  in  any  plant; 

"2.  But  it  is  notably  impaired  as  it  comes 
into  conflict  with  the  tendency  to  resemble  the 
general  line  of  its  ancestry. 

"  3.  This  latter  tendency,  or  atavism,  is  con- 
stant, though  not  strong,  and  scarcely  becomes 
impaired  by  the  intervention  of  a  series  of  gen- 
erations in  which  no  reversion  has  taken  place. 


CROSSING   NOT   AN   END.  107 

"4.  The  tendency  to  resemble  a  near  pro- 
genitor (only  two  or  three  generations  removed), 
on  the  other  hand,  is  very  soon  obliterated  if  the 
given  progenitor  is  different  from  the  bnlk  of 
its  ancestors."  *K 

8.  The  crossing  of  plants  should  be  looked  upon 
as  a  means  or  starting-point,  not  as  an  end.  We 
cross  two  flowers  and  sow  the  seeds.  The  result- 
ing seedlings  may  be  unlike  either  parent.  >  Here, 
then,  is  variation.  The  operator  should  select 
that  plant  which  most  nearly  satisfies  his  ideal, 
and  then,  by  selection  from  its  progeny  and  the 
progeny  of  succeeding  generations,  gradually  ob- 
tain the  plant  which  he  desires.  It  is  only  in 
plants  which  are  propagated  by  asexual  parts — as 
grafts,  cuttings,  layers,  bulbs,  and  the  like  —  that 
hybrids  or  crosses  are  commonly  immediately  val- 
uable; for  in  these  plants  we  really  cut  up  and 
multiply  the  one  individual  plant  which  pleases  us 
in  the  first  batch  of  seedlings,  rather  than  to  take 
the  offspring  or  seedlings  of  it.  Thus,  if  any 
particular  plant  in  a  lot  of  seedlings  of  crosses 
of  cannas,  or  plums,  or  hops,  or  strawberries,  or 
potatoes,  is  valuable,  we  multiply  that  one  in- 
dividual. There  is  no  occasion  for  fixing  the 
variety.  But  any  satisfactory  plant  in  a  lot  of  seed- 
lings of  crosses  of  pumpkins,  or  wheat,  or  beans, 
must  be  made  the  parent  of  a  new  variety  by  sow- 
ing the  seeds  of  it  and  then  by  selecting  for  seed- 


108      HOW   DOMESTIC    VARIETIES    ORIGINATE. 

parents,  year  by  year,  those  plants  which  are  best. 
"  The  unsettled  forms  arising  from  crosses,"  Focke 
writes,  "  are  the  plastic  material  ont  of  which 
gardeners  form  their  varieties." 

But  even  in  the  fruits,  and  other  bud-propa- 
gated plants,  crossing  may  often  be  used  to  as 
good  advantage  for  the  purpose  of  originating 
variation  as  it  can  in  peas  or  buckwheat.  It  only 
requires  a  longer  time  to  fix  and  select  variations 
because  the  plants  mature  so  slowly.  Ordinarily, 
if  the  operator  does  not  find  satisfactory  plants 
amongst  the  seedlings  of  any  cross  of  fruit  trees, 
he  roots  up  the  whole  batch  as  profitless.  But  if 
he  were  to  allow  the  best  plants  to  stand  and 
were  to  sow  seeds  from  them,  the  second  gen- 
eration might  produce  something  more  to  his 
liking.  But  it  is  generally  quicker  to  make 
another  cross  and  to  try  the  experiment  over 
again,  than  to  wait  for  unpromising  seedlings  to 
bear.  This  repeated  repetition  of  the  experiment, 
however,  —  continual  crossing  and  sowing  and 
uprooting,  —  is  gambling.  Throwing  dice  to  see 
what  will  turn  up  is  a  comparable  proceeding. 
The  sowing  of  uncrossed  seed  is  little  better. 
Peter  M.  Gideon  sowed  over  a  bushel  of  apple 
seed,  and  one  seed  produced  the  Wealthy  apple.1 

1  The  facts  in  the  origination  of  the  Wealthy  apple,  as  re- 
lated to  me  by  Mr.  Gideon,  are  these :  he  first  planted  a  bushel 
of  apple  seeds,  and  then  each  year,  for  nine  years,  he  planted 


GUIDES   TO    CROSSING.  109 

D.  B.  Wier  raised  a  million  seedlings  of  soft 
maple,  and  one  plant  of  the  lot  had  finely  divided 
leaves,  and  is  now  Wier's  Cutleaved  maple.  Teas' 
Weeping  mulberry,  which  is  now  so  deservedly 
popular,  was,  as  Mr.  Teas  tells  me,  "  merely  an 
accidental  seedling."  So  this  explains  why  the 
production  of  new  varieties  of  fruits  is  always 
chance,  whilst  a  skilled  man  can  sit  in  his  study 
in  the  winter  time  and  picture  to  himself  a  new 
bean  or  muskmelon,  and  then  go  out  in  the  next 
three  or  four  summers  and  produce  it. 

9.  If  it  is  desired  to  employ  crossing  as  a  direct 
means  of  producing  new  varieties,  each  parent  to  the 
proposed  cross  should  be  selected  in  agreement  with 
the  rules  already  specified,  and  also  because  it  pos- 
sesses in  an  emphatic  degree  one  or  more  of  the 
qualities  which  it  is  desired  to  combine;  and  the 
more  uniformly  and  persistently  the  parent  pre- 
sents a  given  character,  the  greater  is  the  chance  that 
it  will  transmit  that  character.  It  has  already 
been  said  that  crossing  for  the  instant  production 
of  new  varieties  is  most  certain  to  give  valuable 

enough  seed  to  give  a  thousand  trees.  At  the  end  of  ten  years, 
all  the  seedlings  had  perished  (this  was  in  Minnesota)  except 
one  hardy  seedling  crab.  Then  a  small  lot  of  seeds  of  apples 
and  crab  apples  was  obtained  in  Maine,  and  from  these  the 
Wealthy  came.  There  were  only  about  fifty  seeds  in  the 
batch  of  crab  seed  which  gave  the  Wealthy ;  but  before  this 
variety  was  obtained,  much  over  a  bushel  of  seed  had  been 
sown. 


110      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

results  in  those  species  which  are  propagated  by 
buds,  because  the  initial  individual  differences 
are  not  dissipated  by  seed-reproduction.  This 
is  especially  true  of  hybridization,  or  crossing 
between  distinct  species  ;  for  in  such  violent  cross- 
ing as  this  the  offspring  is  particularly  likely  to 
be  unstable  when  propagated  by  seeds.  The  re- 
sults of  hybridization  appear  to  be  most  certain 
in  those  plants  which  are  grown  under  glass,  and 
in  which,  therefore,  the  selection  of  the  seed- 
parents  is  most  carefully  made,  and  where  the 
conditions  of  existence  are  most  uniform.  The 
most  remarkable  results  in  hybridization  which 
have  yet  been  attained  are  with  the  choicer  glass- 
house plants,  such  as  orchids,  begonias,  anthu- 
riums,  and  the  like.      (Lecture  II.) 

The  more  violent  the  cross,  the  less  is  the  likeli- 
hood that  desirable  offspring  will  follow.  Species 
which  refuse  to  give  satisfactory  results  when 
hybridized  directly  or  between  the  pure  stocks, 
may  give  good  varieties  when  the  " blood"  has 
become  somewhat  attenuated  through  previous 
crossings.  The  best  results  in  hybridizing  our 
native  grape  with  the  European  grape,  for  ex- 
ample, have  come  from  the  use  of  one  parent 
which  is  already  a  hybrid.  Two  notable  examples 
are  the  Brighton  and  Diamond  grapes,  raised  by 
Jacob  Moore.  The  Brighton  is  a  cross  of  Con- 
cord (pure  native)  by  Diana-Hamburg  (hybrid  of 


IMPORTANT   HYBRIDS    OF    FRUITS.  Ill 

impure  native  and  European).  Diamond  is  a 
cross  of  Concord  by  Iona,  the  latter  parent  un- 
doubtedly of  impure  origin,  containing  a  trace  of 
the  European  vine.  T.  V.  Munson's  Brilliant  is 
a  secondary  hybrid,  its  parents,  Lindley  and  Dela- 
ware, both  containing  hybrid  blood.  Others  of 
his  varieties  have  similar  histories.  Even  when 
the  cross  is  much  attenuated  —  or  three  or  four 
or  even  more  times  removed  from  a  pure  hybrid 
origin  by  means  of  subsequent  crossings  —  it  may 
still  produce  marked  effects  in  a  cross  without 
introducing  such  contradictory  characters  as  to 
jeopardize  the  value  of  the  offspring. 

Amongst  American  fruit  plants  there  are  com- 
paratively few  valuable  hybrids.  The  most  con- 
spicuous .  ones  are  in  the  grapes,  particularly  the 
various  Rogers  varieties,  such  as  Agawam,  Lind- 
ley, Wilder,  Barry,  and  others,  which  are  hybrids 
of  the  European  grape  and  a  native  species. 
Other  hybrids  are  the  Kieffer  and  allied  pears 
(between  the  common  pear  and  the  Oriental 
pear),  the  Transcendent  and  a  few  other  crabs 
(between  the  common  apple  and  the  Siberian 
crab),  the  Soulard  and  kindred  crabs  (between 
the  common  apple  and  the  native  Western  crab), 
a  few  blackberries  of  the  Wilson  Early  type 
(between  the  blackberry  and  the  dewberry),  the 
purple-cane  raspberries  (between  the  native  red 
and   black   raspberries,    and    possibly    sometimes 


112      HOW   DOMESTIC    VARIETIES    ORIGINATE. 

combined  with  the  European  raspberry),  the 
Utah  Hybrid  cherry  (between  the  Western  sand 
cherry  and  the  sand  plum),  and  probably  a  few 
of  the  native  plums.  There  is  undoubtedly  a 
fertile  field  for  further  work  in  hybridizing  our 
fruits,  particularly  those  of  native  origin,  and 
also  many  of  the  ornamental  plants  ;  the  danger 
is  that  persons  are  apt  to  expect  too  much  from 
hybridization,  and  too  little  from  the  betterment 
of  all  the  other  conditions  which  so  profoundly 
modify  plants.  Violent  hybridizations  generally 
give  unsatisfactory  and  unreliable  results ;  but 
subsequent  crossings,  when  the  "blood"  of  the 
original  species  to  the  contract  is  considerably 
attenuated,  may  be  expected  to  correct  or  over- 
come the  first  incompatibility,  as  explained  above. 
10.  Establish  the  ideal  of  the  desired  variety 
firmly  in  the  mind  before  any  attempt  is  made  at 
plant-breeding.  If  one  is  to  make  any  progress 
in  securing  new  varieties,  he  must  first  be  an 
expert  judge  of  the  capabilities  and  merits  of 
the  plants  with  which  he  is  dealing,  otherwise 
he  may  attempt  the  impossible  or  he  may  obtain 
a  variety  which  has  no  merit.  It  is  important, 
too,  that  the  person  bear  in  mind  the  fact  that 
a  variety  which  is  simply  as  good  as  any  other 
in  cultivation  is  not  worth  introducing.  It 
should  be  better  in  some  particular  than  any 
other  in  existence.     The  operator  must  know  the 


PRODUCE   AN   INITIAL   VARIATION.  113 

points  of  his  plant,  as  an  expert  stock-breeder 
knows  the  points  of  an  animal,  and  he  must 
possess  the  rare  judgment  to  determine  which 
characters  are  most  likely  to  reappear  in  the 
offspring.  Inasmuch  as  a  person  can  be  an  ex- 
pert in  only  a  few  plants,  it  follows  that  he  can- 
not expect  satisfactory  results  in  breeding  any 
species  which  may  chance  to  come  before  him. 
Persistent  and  uniform  effort,  continued  over  a 
series  of  years,  is  generally  demanded  for  the 
production  of  really  valuable  varieties.  Thus  it 
often  happens  that  one  man  excels  all  competitors 
in  breeding  a  particular  class  of  plants.  The  hor- 
ticulturist will  recall,  for  instance,  Lemoine  in 
the  breeding  of  gladiolus,  Eckford  in  peas,  Crozy 
in  c annas,  Bruant  in  pelargoniums,  and  others. 
There  are  now  and  then  varieties  which  arise 
from  no  effort,  but  because  of  that  very  fact  they 
reflect  no  credit  upon  the  so-called  originator, 
who  is  really  only  the  lucky  finder.  So  far  as 
the  originator  is  concerned,  such  varieties  are 
merely  chance.  If,  however,  the  operator  —  him- 
self an  expert  judge  of  the  plant  with  which  he 
deals  —  chooses  his  seeds  with  care  and  discrimi- 
nation, and  then  proposes,  if  need  be,  to  follow  up 
his  work  generation  by  generation  by  means  of 
selection,  the  work  becomes  plant-breeding  of  the 
highest  type. 

First  of  all,  therefore,  the  operator  must  know 


114      HOW   DOMESTIC   VARIETIES    ORIGINATE. 

what  he  can  likely  get,  and  what  will  likely  be 
worth  getting.  Most  persons,  however,  begin  at 
the  other  end  of  the  problem,  —  they  get  what 
they  can,  and  then  let  the  public  judge  if  the 
effort  has  been  worth  the  while. 

11.  Having  obtained  a  specific  and  correct  ideal, 
the  operator  must  next  seek  to  make  his  plant  vary 
in  the  desired  direction.  This  may  be  done  by 
crossing,  or  by  modifying  the  conditions  under 
which  the  plant  grows,  as  indicated  in  Lectures 
I.  and  II.  If  there  are  any  two  plants  which 
possess  indications  of  the  desired  attributes,  cross 
them:  amongst  the  seedlings  there  may  be  some 
which  may  serve  as  starting-points  for  further 
effort. 

A  change  in  the  circumstances  or  environment 
of  the  plant  may  start  the  desired  attribute.  If 
the  plant  must  be  dwarfer,  plant  it  on  poorer  or 
drier  soil,  transfer  it  towards  the  poles,  plant  it 
late  in  the  season,  or  transplant  it  repeatedly  (see 
pages  25  and  143).  Dwarf  peas  become  climb- 
ing peas  on  rich,  moist  soils.  If  the  plant  must 
have  large  fruits,  allow  it  more  food  and  room, 
and  give  attention  to  pruning  and  thinning.  Cer- 
tain geographical  regions  develop  certain  charac- 
ters in  plants,  as  we  have  seen  (page  24);  if, 
therefore,  the  desired  feature  does  not  appear 
spontaneously  or  as  a  result  of  any  other  treat- 
ment, transfer  the  plant  for  a  time  to  that  region 


PRODUCE   AN   INITIAL   VARIATION.  115 

which  is  characterized  by  such  attributes,  if  there 
is  any  such. 

The  importance  of  growing  the  plant  under 
conditions  or  environments  in  which  the  desired 
type  of  characters  is  most  frequently  found,  is 
admirably  emphasized  in  the  evolution  of  varieties 
which  are  adapted  to  forcing  under  glass.  Within 
a  century,  —  and  in  many  instances  within  a 
decade  or  two,  —  species  which  were  practically 
unknown  to  glass-houses  have  produced  varieties 
which  are  perfectly  adapted  to  them.  This  has 
been  accomplished  by  growing  the  most  tractable 
existing  varieties  under  glass,  and  then  carefully 
and  persistently  selecting  those  which  most  com- 
pletely adapt  themselves  to  their  environment  and 
to  the  ideals  of  the  operator.  One  of  the  most 
remarkable  examples  of  this  kind  is  afforded  by 
the  carnation.  In  Europe  it  is  chiefly  a  border 
or  out-door  plant,  but  within  a  generation  it  has> 
produced  hosts  of  excellent  forcing  varieties  in 
America,  where  it  is  grown  almost  exclusively  as 
a  glass-house  flower.  So  the  carnation  types  of 
Europe  and  America  are  widely  unlike,  and  the 
unlikeness  becomes  more  emphatic  year  by  year 
because  of  the  rapid  aberrant  evolution  of  the 
American  forms. 

Sowing  the  seeds  of  hardy  annual  plants  in  the 
fall  often  generates  a  tendency  to  produce  thick- 
ened roots.      The  plant,  finding  itself  unable  to 


116      HOW   DOMESTIC    VARIETIES   ORIGINATE. 

perfect  seeds,  stores  its  reserve  in  the  root,  and 
it  therefore  tends  to  become  biennial.  In  this 
manner,  with  the  aid  of  selection  and  the  varia- 
tion of  the  soil,  Carriere  was  able  to  produce  good 
radishes  from  the  wild  slender-rooted  charlock 
(Raphanns  Raphanistrum) . 

Lessened  vigor,  so  long  as  the  plant  continues 
to  be  healthy,  nearly  always  results  in  a  compara- 
tive increase  of  fruits  or  reproductive  organs. 
It  is  an  old  horticultural  maxim  that  checking 
growth  induces  fruitfulness.  It  is  largely  in  con- 
sequence of  this  fact  that  plants  bear  heaviest 
when  they  attain  approximate  maturity.  Trees 
are  often  thrown  into  bearing  by  girdling,  heavy 
pruning,  the  attacks  of  borers,  and  various  acci- 
dental injuries.  The  gardener  knoAVS  that  if  he 
keeps  his  plants  in  vigorous  growth  by  con- 
stantly potting  them  on  into  larger  pots,  he  will 
get  little,  or  at  least  very  late,  bloom.  The 
plant-breeder,  therefore,  may  be  able  to  induce 
the  desired  initial  variation  by  attention  to  this 
principle.  (See  discussion  of  variation  in  rela- 
tion to  food  supply,  page  16.)  Arthur  has  re- 
cently put  the  principle  into  this  formula  :  "  A 
decrease  in  nutrition  during  the  period  of  growth 
of  an  organism,  favors  the  development  of  the  re- 
productive parts  at  the  expense  of  the  vegetative 
parts." 

A  most  important  means  of  inducing  variation 


SIMULTANEITY   OF   VARIATION.  117 

is  the  simple  change  of  seed,  the  philosophical 
reasons  for  which  are  explained  on  pages  59  and 
28.  A  plant  becomes  closely  fitted  or  accus- 
tomed to  one  set  of  conditions,  and  when  it  is 
placed  in  new  conditions,  it  at  once  makes  an 
effort  to  adapt  itself  to  them.  This  adaptation 
is  variation.  No  doubt  the  free  interchange  of 
seeds  between  seed-merchants  and  customers  is 
one  of  the  most  fertile  causes  of  the  enormous 
increase  in  varieties  in  recent  times. 

When  once  a  novel  variety  appears,  others  of  a 
similar  kind  are  likely  soon  to  follow  in  other 
places,  and  some  persons  have  supposed  that  there 
is  a  synchronistic  variation  in  plants,  or  a  tendency 
for  like  variations  to  appear  simultaneously  in 
widely  separated  localities.  There  is  perhaps 
some  remote  reason  for  this  belief,  because  there 
is,  as  Darwin  expresses  it,  an  accumulative  effect 
of  domestication  or  cultivation,  by  virtue  of  which 
plants  which  long  remain  comparatively  invariable 
may  within  a  short  time,  when  cultivation  has 
been  continued  long  enough,  vary  widely  and  in 
many  directions;  and  it  is  to  be  expected  that 
even  when  plants  have  long  since  responded  to 
the  wishes  of  the  cultivator,  an  equal  amount  or 
accumulation  of  the  force  of  domestication  would 
tend  to  produce  like  effects  in  different  places. 
But  it  is  probable  that  by  far  the  greater  part  of 
this  synchronistic  variation  is  simply  an  apparent 


118      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

one,  for  whenever  any  marked  novelty  appears  the 
attention  of  all  interested  persons  is  directed  to 
looking  for  similar  variations  amongst  their  own 
plants. 

12.  The  person  who  is  wishing  for  new  varieties 
should  look  critically  to  all  perennial  plants,  and 
particularly  to  trees  and  shrubs,  for  bud-varieties 
or  sports.  It  has  already  been  said  (pages  28,  6) 
that  the  branches  of  a  tree  may  vary  amongst 
themselves  in  the  same  way  in  which  seedlings 
vary,  and  for  the  same  reasons.  As  a  rule,  any 
marked  sport  is  capable  of  being  perpetuated  by 
bud-propagation.  The  number  of  bud- varieties 
now  in  cultivation  is  really  very  large.  Many  of 
the  cut-leaved  and  colored  or  variegated  varieties 
of  ornamental  plants  were  originally  found  upon 
other  trees  as  sports.  The  "  mixing  in  the  hill  " 
of  potatoes  is  bud-variation.  Nectarines  are 
derived  from  the  peach,  some  of  them  as  sports 
and  some  as  seedlings.  The  moss-rose  was  prob- 
ably originally  a  sport  from  the  Provence  rose. 
Greening  apple  trees  often  bear  russet  apples,  and 
russet  trees  sometimes  bear  greenings.  So  far  as 
I  know,  there  are  no  varieties  of  annual  plants 
which  have  originated  as  sports.  The  probable 
reason  for  this  is  the  fact  that  the  duration  of  the 
plant  is  short  and  that  its  constitution  is  not  pro- 
foundly modified  in  a  single  generation  by  the 
new  circumstances   in  which  it  is  placed  every 


BUD-VAEIETIES.  119 

year.  The  effects  of  the  conditions  in  which  it 
lives  are  recorded  in  the  seeds,  and  the  plant  dies 
without  allowing  a  second  season  of  growth  to 
express  the  impressions  which  were  received  in 
a  former  generation.  The  fact  that  every  branch 
of  an  annual  plant  —  as  of  perennials  —  is  unlike 
every  other  branch,  is  evidence  enough  that  the 
annual  is  not  unlike  the  perennial  in  fundamental 
constitution  ;  and  there  is  every  reason  to  believe 
that  if  any  given  annual  were  to  become  a  peren- 
nial, it  would  now  and  then  develop  differences 
sufficiently  pronounced  to  make  them  worthy  the 
name  of  sports,  the  same  as  hyacinths,  bouvardias, 
trees,  and  all  other  perennial  plants  are  apt  to  do. 
Bud- varieties  may  not  only  come  true  from  buds 
—  as  grafts,  cuttings  and  layers,  —  but  they  occa- 
sionally perpetuate  themselves  by  seeds.  Now, 
these  seedlings  are  amenable  to  selection,  just  the 
same  as  any  other  seedlings  are ;  the  bud-variety, 
therefore,  may  give  the  initial  starting-point  for 
plant-breeding.  But,  more  than  this,  it  is  some- 
times possible  to  improve  and  fix  the  type  by 
bud-selection  as  well  as  by  seed-selection.  Dar- 
win cites  this  interesting  testimony  :  "  Mr.  Salter 
brings  the  principle  of  selection  to  bear  on  varie- 
gated plants  propagated  by  buds,  and  has  thus 
greatly  improved  and  fixed  several  varieties.  He 
informs  me  that  at  first  a  branch  often  produces 
variegated  leaves  on  one  side  alone,  and  that  the 


120      HOW   DOMESTIC    VARIETIES   ORIGINATE. 

leaves  are  marked  only  with  an  irregular  edging, 
or  with  a  few  lines  of  white  and  yellow.  To  im- 
prove and  fix  such  varieties,  he  finds  it  necessary 
to  encourage  the  buds  at  the  bases  of  the  most 
distinctly  marked  leaves  and  to  propagate  from 
them  alone.  By  following,  with  perseverance,  this 
plan  during  three  or  four  successive  seasons  a  dis- 
tinct and  fixed  variety  can  generally  be  secured." 
Ernest  Walker,  a  careful  gardener  at  New  Albany, 
Indiana,  is  of  the  opinion  that  the  abnormal  char- 
acter of  sports  often  intensifies  itself  if  the  sport 
is  allowed  to  remain  upon  the  parent  plant  for  a 
considerable  time.  He  has  observed  this  particu- 
larly in  coleus,  where  color  sports  are  frequent. 
"In  these,"  he  says,  "the  sport  begins  with  a 
branch,  which  may  be  taken  off  and  propagated  as 
a  new  variety.  If  left  on  the  parent,  other  parts 
of  the  plant  are  apt  to  show  similar  variations. 
Indeed,  I  think  it  is  not  best  to  be  in  too  great  a 
hurry  to  remove  a  sporting  branch,  for  its  char- 
acter seems  to  tend  to  become  more  fixed  if  it 
remains  on  the  plant." 

13.  The  starting-point  once  given,  all  permanent 
progress  lies  in  continued  selection.  This,  as  I  have 
already  pointed  out,  is  really  the  key  to  the  whole 
matter.  In  the  greater  number  of  cases,  the  oper- 
ator cannot  produce  the  initial  variation  which  he 
desires,  but,  by  looking  carefully  amongst  many 
plants,  he  may  find  one  which  shows  an  indication 


SELECTION   THE    KEY-NOTE.  121 

of  his  ideal.  This  plant  must  be  carefully  saved, 
and  all  the  seeds  sown  in  a  place  where  crossing 
with  other  types  cannot  take  place.  Of  a  hun- 
dred seedlings  from  this  plant,  mayhap  one  or 
two  will  still  further  emphasize  the  character 
Avhich  is  sought.  These,  again,  are  saved  and  all 
the  seeds  are  sown.  So  the  operation  goes  on, 
patiently  and  persistently,  and  there  is  reward 
at  the  end.  This  is  the  one  eternal  and  funda- 
mental principle  which  underlies  the  amelioration 
of  plants  under  the  touch  of  man  ;  and  because 
we  know,  from  experience,  that  it  is  so  important, 
Ave  are  sure,  as  Darwin  was,  that  selection  in 
nature  must  be  the  most  potent  factor  in  the 
progress  of  the  vegetable  world. 

But  suppose  this  suggestion  of  the  new  variety 
does  not  appear  amongst  the  batch  of  plants 
which  Ave  raise?  Then  soav  again;  vary  the  con- 
ditions; select  the  most  widely  variable  types; 
cross ;  at  length  —  if  the  ideal  is  true  —  the  sug- 
gestion will  come.  "Cultivation,  diversification 
of  the  conditions  of  existence,  and  repeated  sow- 
ings "  are  the  means  which  Verlot  would  employ 
to  induce  variations.  But  the  skill  and  the  char- 
acter of  the  final  result  lie  not  so  much  in  the 
securing  of  the  initial  start,  as  in  the  subsequent 
selection.  Nature  affords  starting-points  in  end- 
less number,  but  there  are  feAv  men  alert  and  skil- 
ful enough  to  take  the  hint  and  improve  it.     If  I 


122      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

want  a  new  tomato,  I  first  endeavor  to  discover 
what  I  want.  I  decide  that  I  must  have  one  like 
the  Acme  in  color,  but  more  spherical,  with  a 
firmer  flesh,  and  a  little  earlier.  Then  I  shall 
raise  an  acre  of  Acme  tomatoes,  and  closely  allied 
varieties  ;  or  if  I  cannot  do  that,  I  make  arrange- 
ments to  inspect  my  neighbor's  fields.  I  scruti- 
nize every  plant  as  the  first  fruits  are  ripening. 
Finally,  I  find  one  plant  —  not  one  fruit  —  which 
is  something  like  the  variety  which  I  desire. 
Very  Avell !  Wait  two  to  five  years,  and  you  shall 
see  my  new  variety ! 

Some  of  these  initial  variations  possess  no  ten- 
dency to  reproduce  themselves.  The  seedlings  of 
them  may  break  up  into  a  great  diversity  of 
forms,  no  form  representing  the  parent  closely. 
In  such  cases,  it  is  generally  useless  to  proceed 
further  with  this  brood.  Another  start  should  be 
made  with  another  plant.  So  it  is  always  impor- 
tant, as  we  have  already  seen  (Rule  6),  to  have  as 
many  starting-points  as  possible,  to  lessen  the  risk 
of  failure.  Whilst  it  requires  nice  judgment  to  se- 
lect those  plants  which  possess  the  most  important 
and  the  most  transmissible  combination  of  charac- 
ters, the  greatest  skill  is  nevertheless  required  to 
carry  forward  a  correct  system  of  selection. 

14.  Even  when  the  desired  variety  is  obtained,  it 
must  be  kept  up  to  the  standard  by  constant  attention 
to  selection.     That  is,  there  is  no  real  stability  in 


SELECTION    TO    MAINTAIN    PURITY.  123 

the  forms  of  plant  life.  So  long  as  the  conditions 
of  existence  vary,  so  long  will  plants  make  the 
effort  to  adapt  themselves  to  the  changes.  No 
two  seasons  are  alike,  and  no  two  fields,  or  even 
parts  of  fields,  are  alike  ;  and  there  are  no  two 
cultivators  who  give  exactly  the  same  and  equal 
attention  to  tillage,  fertilizing,  and  the  other 
treatments  of  plants.  All  forms  or  varieties, 
therefore,  tend  to  "run  out"  by  variation  or 
gradual  evolution  into  other  forms ;  hut  because 
we  keep  the  same  name  for  all  the  succeeding 
generations,  we  fancy  that  we  still  have  the  same 
variety.  In  1887  I  found  a  single  tomato  plant 
in  my  garden  in  Michigan,  which  had  several 
points  of  superiority  over  any  other  of  the  one 
hundred  and  seventy  varieties  which  I  was  then 
growing.  It  came  from  a  packet  of  German  seed 
of  an  inferior  variety.  The  tomato  was  very 
solid,  an  unusually  long  keeper,  productive,  and 
attractive  in  size  and  appearance.  The  variation 
was  so  promising  that  I  named  it  in  a  sketch  of 
tomatoes  which  I  published  that  year,  calling  it 
the  Ignotum  (that  is,  unknown),  to  indicate  that 
the  origin  of  it  was  no  merit  of  my  own.  I  sent 
seeds  to  a  few  friends  for  testing.  I  sowed  the 
seeds  for  about  five  hundred  plants  in  1888  in 
an  isolated  patch  upon  uniform  soil.  The  larger 
part  of  the  plants  were  more  or  less  like  the 
parent.     A    few    reverted.      A   few   of   the   best 


324      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

plants  were  selected,  and  the  seed  saved.  I 
then  moved  to  New  York  and  took  the  seed  with 
me.  This  was  sown  in  uniform  soil  in  an  iso- 
lated position  in  1889.  This  crop,  probably  as 
a  result  of  the  careful  selection  of  the  year  before 
and  of  the  change  of  locality,  was  remarkably 
uniform  and  handsome.  Of  the  442  plants  which 
I  grew  that  year,  none  reverted  to  the  little 
Eiformige  Dauer,  the  German  variety  from  which 
it  had  come,  but  there  was  some  variation  in  them 
due  to  different  methods  of  treatment.  I  again 
saved  the  seeds,  and  I  was  now  read}7  to  intro- 
duce the  variety.  I  therefore  sold  my  seed,  six 
pounds,  to  V.  H.  Hallock  &  Son,  Queens,  New 
York,  who  introduced  it  in  1890.  The  very  next 
year,  1891,  I  obtained  the  Ignotum  from  fifteen 
dealers  and  grew  the  plants  side  by  side.  Of  the 
fifteen  lots,  eight  bore  small  and  poor  fruits  which 
were  not  worth  growing  and  which  could  not  be  rec- 
ognized as  Ignotum !  Grown  from  our  own  seed, 
it  still  held  its  characters  well.  Here,  then,  only 
a  year  after  its  introduction,  half  the  seedsmen 
were  selling  a  spurious  stock.  It  is  possible  that 
some  of  this  variation  arose  from  substitution  of 
other  varieties  by  seedsmen,  although  I  have  yet 
secured  no  evidence  of  any  unfair  dealing.  It  is 
possible,  also,  that  the  product  of  some  of  the 
samples  which  I  early  sent  out  for  testing  had 
found  their  way  into  seedsmen's  hands.     But  I  am 


DURATION    OF   VARIETIES.  125 

convinced  that  very  much  of  this  variation  was 
a  legitimate  result  of  the  various  conditions  in 
which  the  crops  of  1890  had  been  grown,  and  the 
varying  ideals  of  those  who  saved  the  seeds.  I 
am  the  more  positive  of  this  from  the  fact  that 
the  Ignotum  tomato,  as  I  first  knew  it  and  bred 
it,  appears  to  be  lost  to  cultivation,  although  the 
name  is  still  used  for  the  legitimate  family  of 
descendants  from  my  original  stock.  All  this 
experience  illustrates  how  quickly  varieties  pass 
out  by  variation  and  by  the  unconscious  and 
unlike  selection  practised  by  different  persons. 

The  duration  of  any  variety  is  inversely  propor- 
tional to  the  frequency  of  its  generations.  Annual 
plants,  other  conditions  being  the  same,  run  out 
sooner  than  perennials,  because  seed-reproduc- 
tion—  or  the  generations  —  intervenes  more  fre- 
quently. Trees,  on  the  other  hand,  carry  their 
variations  longer,  because  the  seed-generations  — 
in  which  departures  chiefly  take  place  —  are  far- 
ther apart.  Of  all  the  so-called  fruit  plants,  the 
strawberry  runs  out  soonest  and  the  varieties 
change  the  oftenest,  because  a  new  generation  can 
be  brought  into  fruit-bearing  in  two  years,  whilst 
it  may  require  a  decade  or  more  to  bring  a  new 
generation  of  apples  or  chestnuts  into  bearing. 
Yet,  my  reader  will  remind  me  that  the  Wilson 
strawberry  has  been  and  is  the  leading  variety  in 
many  places    for    nearly  forty  }rears,  to  which   I 


126      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

reply  that  tlie  Wilson  of  to-day  is  not  necessarily 
the  same  as  that  introduced  by  James  Wilson, 
simply  because  the  name  is  the  same.  Every  dif- 
ferent soil  or  treatment  tends  to  produce  a  different 
strain  or  variation  in  the  Wilson  strawberry,  as  it 
does  in  any  other  plant  ;  and  every  grower,  when 
setting  a  new  plantation,  selects  his  plants  from 
that  part  of  his  field  which  pleases  him  best, 
rather  than  from  those  plants  which  most  nearly 
correspond  to  the  original  tj])G  of  the  Wilson. 
That  is,  this  unconscious  selection  on  the  part  of 
the  grower  takes  no  account  of  what  the  variety 
was,  but  only  of  what  it  ought  to  be,  and  this 
ideal  differs  with  every  person.  It  is  not  surpris- 
ing, therefore,  to  find  strains  of  Wilson  strawberry 
which  are  as  unlike  as  many  named  varieties  are  ; 
and  it  is  to  be  expected  that  all  of  the  strains  now 
in  existence  have  departed  considerably  from  the 
original  type. 

This  example  borrowed  from  the  strawberry  is 
a  most  important  one,  because  it  illustrates  how  a 
variety  may  vary  and  pass  out  of  existence  even 
though  it  is  propagated  wholly  asexually,  or  by 
buds.  There  are  to-day  several  different  types  of 
Rhode  Island  Greening  apple  in  cultivation,  which 
have  originated  from  variations  produced  by  envi- 
ronment and  by  the  different  models  which  propa- 
gators have  had  in  mind ;  and  the  same  is  true  of 
many  other  fruits. 


AMELIORATION   DUE   TO    SELECTION.  127 

All  the  foregoing  remarks  demonstrate  the 
importance  of  constant  attention  to  selection  if 
one  desires  to  maintain  the  exact  type  of  any 
variety  which  he  has  produced.  They  explain 
the  value  of  the  "roguing" —  or  systematic  de- 
struction of  all  "  rogues  "  or  non-typical  plants  — 
which  is  invariably  practised  by  all  good  seed- 
growers.  But  they  still  more  emphatically  show 
that  every  variety  is  essentially  unstable,  and  that 
the  only  abiding  result  is  constant  evolution,  the 
old  forms  being  left  behind  as  the  type  expands 
into  new  and  better  strains.  Varieties  to  be  valu- 
able, therefore,  ought  not  to  be  rigidly  fixed,  and, 
fortunately,  nature  has  prescribed  that  they  can- 
not be.  Probably  every  decade  sees  a  complete 
change  in  every  variety  of  any  annual  species 
which  is  propagated  exclusively  from  seeds,  and 
every  century  must  see  a  like  change  in  the  tree 
fruits.  These  changes  are  so  gradual,  and  the 
original  basis  of  comparison  fades  away  so  com- 
pletely, that  we  generally  fail  to  recognize  the 
evolution. 

15.  It  is  evident,  therefore,  that  the  most  abiding 
progress  in  the  amelioration  of  plants  must  come  as  a 
result  of  the  very  best  cultivation  and  the  most  intel- 
ligent selection  and  change  of  seed.  Every  reflec- 
tive person  must  admit  that  the  cultivation  of 
plants  —  which  is  the  fundamental  conception  of 
agriculture  —  has  been  and  is  crude  and  imperfect, 


128      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

and  that  there  has  been  no  conscious  effort  on  the 
part  of  the  human  race  to  produce  any  given  final  re- 
sult upon  the  cultivated  flora.  Yet,  this  imperfect 
cultivation  has  already  modified  plants  so  pro- 
foundly that  we  cannot  determine  the  originals  of 
many  of  them,  and  we  can  trace  the  evolution  of 
but  few.  The  science  of  rural  industry  is  now 
fairly  well  understood  in  it's  essential  fundamental 
principles,  and  the  intelligence  of  those  classes  of 
persons  who  deal  with  plants  is  rapidly  enlarging. 
The  opening  of  the  twentieth  century  will  virtu- 
ally mark  a  new  era  for  agriculture,  and  from 
that  time  on  the  onward  evolution  of  plants  should 
proceed  confidently  and  unchecked.  Our  eyes  are 
too  often  dazzled  by  the  novelties  which  suddenly 
thrust  themselves  upon  us,  and  we  look  for  some 
mystic  power  which  shall  enable  us  to  produce 
varieties  forthwith  at  our  will.  We  need  not  so 
much  varieties  with  new  names  as  we  do  a  general 
increase  in  productiveness  and  efficiency  of  the 
types  which  we  already  possess  ;  and  this  augmen- 
tation must  come  chiefly  in  the  form  of  a  gradual 
evolution  under  the  stimulus  of  good  care.  The 
man  who  will  accomplish  most  for  the  amelioration 
and  unfolding  of  the  forms  of  plants,  is  he  who 
fixes  his  eyes  steadily  upon  the  future,  and  with 
the  inspiration  of  a  long  forecast,  urges  the  better- 
ment of  all  conditions  in  which  plants  grow. 


DEWBERRY   AND   BLACKBERRY.  129 

III.    Specific  Examples. 

The  foregoing  principles  and  discussions  will 
become  more  concrete  if  a  few  actual  examples  of 
the  origination  of  varieties  are  given.  In  order 
to  begin  with  a  very  simple  case,  I  will  relate  the 
introduction  of  the  varieties  of  dewberries,  for 
this  fruit  is  yet  little  cultivated,  the  varieties  are 
few,  and  the  domestication  of  it  is  not  yet  thirty 
years  old. 

The  Dewberry  and  Blackberry. 

The  dewberries  are  native  fruits,  and  it  is  only 
within  the  last  ten  years  that  they  have  become 
prominent  among  fruit-growers.  The  most  impor- 
tant one  is  the  Lucretia.  This  was  found  grow- 
ing wTild  upon  a  plantation  in  West  Virginia  in 
war  time.  In  1876,  a  few  of  the  plants  were  sent 
to  Ohio,  and  from  this  start  the  present  stock  has 
come.  It  is  probable  that  similar  wild  varieties  are 
growing  to-day  in  many  parts  of  the  country,  but 
they  have  not  chanced  to  have  been  seen  by  per- 
sons who  are  interested  in  cultivating  them.  It  is 
a  form  of  the  common  wild  dewberry,  which  grows 
all  over  the  northeastern  states.  Just  why  this 
particular  patch  in  West  Virginia  should  have  been 
so  much  better  than  the  general  run  of  the  species, 
nobody  knows,  but  it  was  undoubtedly  the  prod- 
uct of  some  local  environment  of  soil  or  position. 


130      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

Early  in  the  seventies,  T.  C.  Bartel,  of  Huey, 
Clinton  Co.,  Illinois,  observed  very  excellent  dew- 
berries growing  in  rows  between  the  lines  of 
stubble  in  an  old  cornfield,  where  the  plant  had 
evidently  been  quick  to  avail  itself  of  unoccupied 
land.  This  was  introduced  as  the  Bartel  dew- 
berry, and  is  now  the  second  in  point  of  promi- 
nence amongst  the  cultivated  varieties.  Other 
varieties  have  appeared  in  much  the  same  way. 
A  fruit-grower  in  Michigan  found  an  extra  good 
dewberry  in  a  neighboring  wood-lot,  and  intro- 
duced it  under  the  name  of  Geer,  in  compliment 
to  the  owner  of  the  place.  In  Florida,  an  un- 
usually good  plant  of  the  common  wild  dewberry 
of  that  region  was  discovered,  and  introduced  by 
Reasoner  Brothers,  under  the  name  of  Manatee. 
There  are  now  about  twenty  named  varieties  of 
dewberries  in  cultivation,  as  described  in  our 
horticultural  writings,  all  of  which,  so  far  as  I 
know,  are  chance  plants  from  the  wild. 

As  the  dewberries  become  more  widely  grown, 
good  seedlings  will  now  and  then  appear  in  cul- 
tivated ground,  and  these  will  be  named  and 
sold.  After  a  time  persons  will  begin  to  sow 
seeds  for  the  purpose  of  producing  new  varieties  ; 
and  those  seedlings  which  chance  to  possess  un- 
usual merit  will  be  propagated,  and  in  due  time 
introduced.  This  is  the  history  of  the  cultivated 
blackberries    and    raspberries    which    have    come 


EVOLUTION   OF   THE   APPLE  131 

from  the  wild  plants  in  less  than  half  a  century. 
These  fruits  are  now  so  far  developed  that  we  no 
longer  think  of  looking  to  the  woods  and  copses 
for  new  varieties  of  promise,  but  the  novelties  are 
mostly  chance  seedlings  from  cultivated  varieties. 
A  few  years  ago  a  friend  purchased  plants  of  the 
Snyder  blackberry.  When  they  came  into  bear- 
ing he  noticed  that  one  plant  was  better  than  the 
rest.  It  bore  larger  fruits,  and  the  bearing  season 
was  longer.  He  took  suckers  from  this  plant, 
and  from  these  others  were  taken,  until  he  now  has 
a  large  plantation  of  the  novelty,  mostly  selected 
from  plants  which  pleased  him  best.  The  variety 
has  such  distinct  merit  that  I  have  named  it  the 
Mersereau,  in  honor  of  the  man  who  recognized 
and  propagated  it.  He  will  continue  selecting 
from  the  best  plants,  as  he  propagates  year  by 
year,  and  it  may  be  that  in  a  few  years  he  will 
have  so  much  improved  it  that  it  will  no  longer 
be  the  variety  with  which  he  started. 

The  Apple. 

The  original  apple  is  not  definitely  known,  but 
it  was  certainly  a  very  small  and  inferior,  crabbed 
fruit,  borne  mostly  in  clusters.  When  we  first 
find  it  described  by  historians,  it  was  still  of  small 
value.  Pliny  said  that  some  kinds  were  so  sour 
as  to  take  the  edge  off  a  knife.     But  better  and 


132      HOW   DOMESTIC    VARIETIES    ORIGINATE. 

better  seedlings  continued  to  come  up  about  habi- 
tations, until,  when  printed  descriptions  of  fruits 
began  to  be  made,  three  or  four  hundred  years 
ago,  there  were  many  named  kinds  in  existence. 
The  size  had  vastly  improved,  and  Avith  this  in- 
crease came  the  reduction  of  the  number  of  fruits 
in  the  cluster;  so  that,  at  the  present  time,  whilst 
apple  flowers  are  borne  in  clusters,  the  fruits  are 
generally  borne  singly.  That  is,  most  of  the 
flowers  fail  to  set  fruit,  and  they  complete  their 
mission  when  they  have  shed  their  pollen  for  the 
benefit  of  the  one  which  persists. 

The  American  colonists  brought  with  them  the 
staple  varieties  of  the  mother  countries.  But 
the  needs  of  the  new  country  were  unlike  those 
of  the  old,  and  the  tastes  and  fashions  of  the 
people  were  changing.  So,  as  seedlings  came  up 
about  the  buildings  and  along  the  fences,  where 
the  seeds  had  been  scattered,  the  ones  which  prom- 
ised to  satisfy  the  new  needs  best  were  saved,  and 
many  of  the  old  varieties  were  allowed  to  pass 
away.  In  1817,  the  date  of  the  first  American 
fruit-book,  over  sixty  per  cent  of  the  varieties 
particularly  recommended  for  cultivation  in  this 
country  were  of  American  origin.  In  1845, 
nearly  two  hundred  varieties  of  apples  were  de- 
scribed as  having  been  fruited  in  this  country, 
of  which  over  half  were  of  American  origin.  Be- 
tween  these  two  dates,  introductions   of  foreign 


EVOLUTION    OF   THE   APPLE.  133 

varieties  had  been  freely  made,  so  that  the  per- 
centage  of  domestic  varieties  had  fallen.  But 
the  next  thirty  years  saw  a  great  change.  Of 
1823  varieties  described  in  1872,  nearly  or  quite 
seventy  per  cent  were  American,  and  a  still  greater 
proportion  of  the  most  prized  kinds  were  of 
domestic  origin.  In  the  older  states,  the  apple 
had  now  become  so  thoroughly  accustomed  to  its 
environment,  and  the  tastes  of  the  people  were 
so  well  supplied,  that  there  was  no  longer  much 
need  for  the  introduction  of  foreign  kinds.  It 
was  not  so  in  the  Northwest.  There  the  apples 
of  the  eastern  states  did  not  thrive.  The  climate 
was  too  cold  and  too  dry.  Attention  was  turned 
to  other  countries  with  similar  or  rigorous  cli- 
mate. In  1870,  the  Department  of  Agriculture 
at  Washington  imported  cions  of  many  varieties 
of  apples  from  Russia;  but  these  did  not  satisfy 
many  fruit-growers  of  the  northern  states.  It 
was  then  conceived  that  the  great  interior  plain 
of  Russia  should  yield  apples  adapted  to  the  upper 
Mississippi  valley,  whilst  those  already  imported 
had  come  from  the  seaboard  territory.  Accord- 
ingly, early  in  the  eighties,  Charles  Gibb,  of  the 
province  of  Quebec,  and  Professor  Budd,  of  Iowa, 
went  to  Russia  to  introduce  the  promising  fruits 
of  the  central  plain.  The  result  has  been  a  most 
interesting  one  to  the  pacific  looker-on.  There 
are  ardent  advocates  of  the  Russian  varieties,  and 


134      HOW    DOMESTIC    VARIETIES    ORIGINATE. 

there  are  others  who  see  nothing  good  in  them. 
There  are  those  avIio  believe  that  all  progress 
must  come  by  securing  seedlings  from  the  hardi- 
est varieties  of  the  eastern  states;  there  are  others 
who  would  derive  everything  from  the  Siberian 
crabs,  and  still  others  who  believe  that  the  final 
result  lies  in  improving  the  native  crabs.  There 
is  no  end  of  discussion  and  cross-purposes.  In 
the  meantime,  nature  is  quietly  doing  the  work. 
Here  is  a  good  seedling  of  some  old  variety,  there 
a  good  one  from  some  Russian,  and  now  and  then 
one  from  the  crab  stocks.  The  new  varieties  are 
gradually  supplanting  the  old,  so  quietly  that  few 
people  are  aware  of  it;  and  by  the  time  the  con- 
testants are  done  disputing,  it  will  be  found  that 
there  are  no  Russians  and  no  eastern  apples,  but 
a  brood  of  northwestern  apples  which  have  grown 
out  of  the  old  confusion. 

All  these  new  apples  are  simply  seedlings, 
almost  all  of  them  chance  trees  which  come  up 
here  and  there  wherever  man  has  allowed  nature 
a  bit  of  ground  upon  which  to  make  garden  as 
she  likes.  In  1892,  there  were  878  varieties  of 
apples  offered  for  sale  by  American  nurserymen, 
and  it  is  doubtful  if  one  in  the  whole  lot  was  the 
result  of  any  attempt  on  the  part  of  the  originator 
to  produce  a  variety  with  definite  qualities.  And 
Avhat  is  true  of  the  apple,  is  about  equally  true 
of  the  other  tree  fruits.     In  the  small  fruits  and 


BEANS.  135 

the  grapes,  where  the  generations  are  shorter  and 
the  results  quicker,  more  has  been  done  in  the 
way  of  direct  selection  of  seeds  and  the  crossing 
of  chosen  parents;  but  even  here,  the  methods 
are  mostly  haphazard. 

Beans. 

Perhaps  there  are  no  plants  more  tractable  in 
the  hands  of  the  plant-breeder  than  the  garden 
beans.  Some  two  or  three  years  ago,  a  leading 
eastern  seedsman  conceived  of  a  new  form  of  bean 
pod  which  would  at  once  commend  itself  to  his 
customers.  He  was  so  well  convinced  of  the 
merits  of  this  prospective  variety,  that  he  made 
a  descriptive  and  "  taking  "  name  for  it.  He  then 
wrote  to  a  noted  bean-raiser,  describing  the  pro- 
posed variety  and  giving  the  name.  "  Can  you 
make  it  for  me  ?  "  he  asked.  "  Yes,  I  will  make 
you  the  bean,"  replied  the  grower.  The  seeds- 
man then  announced  in  his  catalogue  that  he 
would  soon  introduce  a  new  bean,  and,  in  order 
to  hold  the  name,  he  published  it,  along  with  the 
announcement.  Two  years  later,  I  visited  the 
bean-grower.  "  Did  you  get  the  bean  ?  "  I  asked. 
"Yes,  here  it  is."  Sure  enough,  he  had  it,  and  it 
answered  the  requirements  very  well.  Another 
seedsman  would  like  a  round-podded,  stringless, 
green-podded    bean.      This    same    man    produced 


136      HOW   DOMESTIC    VARIETIES    ORIGINATE. 

it,  and  J  went  into  a  field  of  fifteen  acres  of  it, 
where  it  was  growing  for  seed,  and  the  most  fas- 
tidious person  could  not  have  asked  for  a  closer 
approach  to  the  ideal  which  the  breeder  had  set 
before  him  some  four  or  five  years  before. 

How  is  all  this  done  ?  It  looks  simple  enough. 
The  ideal  is  established  first  of  all.  The  breeder 
revolves  it  in  his  mind,  and  eliminates  all  the 
impracticable  and  contradictory  elements  of  it. 
Then  he  goes  carefully  and  critically  through  his 
bean  fields,  particularly  those  varieties  which  are 
most  like  the  desired  kind,  and  marks  those  plants 
which  most  nearly  approach  his  ideal  The  seeds 
of  these  are  carefully  saved,  and  they  are  planted 
in  isolated  positions.  If  he  finds  no  promising 
variations  amongst  his  plantations,  then  he  must 
start  off  the  variation  in  some  other  way.  This 
is  usually  done  by  crossing  those  varieties  which 
are  most  like  the  proposed  kind.  He  has  got  a 
start ;  but  now  the  science  and  skill  begin.  Year 
by  year  he  selects  just  those  plants  which  please 
him  best  and  which  he  judges,  from  experience, 
will  most  surely  carry  their  features  over  to  the 
offspring.  He  starts  with  one  plant ;  the  next 
year  he  may  have  only  two.  If  he  has  ten  or 
twenty  good  ones,  then  the  task  is  an  easy  one, 
for  the  variety  has  elements  of  permanence  —  that 
is,  of  hereditability  —  in  it.  But  he  may  have  no 
plants  the  second  year.     In  that  case,  he  begins 


BEANS.  137 

again  ;  for  if  the  ideal  is  true,  it  can  be  attained. 
This  bean-breeder  to  whom  I  have  referred,  and 
upon  whom  many  of  our  best  seedsmen  rely  for 
new  varieties,  tells  me  that  he  has  discarded  fully 
three  thousand  varieties  and  forms  as  profitless. 
This  only  means  that  he  is  a  most  astute  judge 
of  beans,  and  that  he  knows  when  any  type  is 
likely  to  prove  to  be  a  poor  breeder. 

The  bean  also  affords  an  excellent  example  of 
the  care  which  it  is  generally  necessary  to  exercise 
to  keep  any  variety  true  to  the  type.  The  person 
of  whom  I  have  spoken,  in  common  with  all  care- 
ful seed-growers,  searches  his  field  with  great 
pains  to  discover  the  "rogues,"  or  those  plants 
which  vary  perceptibly  from  the  type  of  the  given 
variety.  The  rogue  may  be  a  variation  in  size  or 
habit  of  plant,  season  of  maturity,  color  or  form 
of  pods,  productiveness,  susceptibility  to  rust,  or 
other  aberrance.  In  the  dwarf  or  bush  beans, 
which  are  now  most  exclusively  grown,  the  most 
frequent  rogue  is  a  climbing  or  half-climbing 
plant.  This  is  a  reversion  to  the  ancestral  type 
of  the  bean,  which  was  no  doubt  a  twining  plant. 
This  rogue  is  always  destroyed,  even  though  it 
may  be,  itself,  a  good  bean.  In  some  cases,  the 
men  who  perform  the  roguing  are  sent  along 
every  row  of  a  whole  field  on  their  hands  and 
knees,  critically  examining  every  plant.  The  ef- 
fect of  this  continual  selection  is  always  to  push 


138      HOW   DOMESTIC    VARIETIES    ORIGINATE. 

on  the  variety  to  greater  excellence.  The  vari- 
ous "  improved  "  strains  of  plants  are  obtained  in 
essentially  this  fashion.  If  the  grower  has  been 
painstaking  with  his  roguing,  he  soon  finds  that 
his  seed  gives  better  and  more  uniform  crops  than 
the  common  stock  of  the  variety.  If  the  improve- 
ment is  marked,  he  may  dignify  his  strain  with 
a  distinct  name,  and  it  thereby  becomes  a  new 
variety.  The  improvement  may  be  a  very  im- 
portant one  to  a  careful  bean-grower,  and  at  the 
same  time  be  so  slight  as  to  escape  the  attention 
of  the  general  farmer,  or  even  of  experimenters 
who  are  not  particularly  skilled  in  judging  the 
merits  of  beans. 

All  these  examples  drawn  from  the  bean  are 
excellent  illustrations  of  the  best  and  most  scien- 
tific plant-breeding,  and  the  same  methods  —  varied 
to  suit  the  different  needs  —  apply  to  the  ameliora- 
tion of  all  other  plants.  The  recent  dwarf  Lima 
beans  may  be  cited  as  examples  of  accidental  or 
fortuitous  varieties,  in  which  the  preconstructed 
ideal  of  the  plant-breeder  had  no  place.  Four  or 
five  of  these  beans  have  attained  some  prominence. 
Henderson  and  Kumerle  dwarf  Limas  were  intro- 
duced in  1889,  Burpee  in  1890,  and  Barteldes  in 
1892  or  1893.  The  variety  which  is  now  called 
the  Henderson  was  picked  up  twenty  or  more 
years  ago  by  a  negro,  who  found  it  growing  along 
a  roadside  in  Virginia.     It  was  afterwards  grown 


BEANS.  139 

in  various  gardens,  and  about  1885  it  fell  into  tlie 
hands  of  a  seedsman  in  Richmond.  Henderson 
purchased  the  stock  of  it  in  1887,  grew  it  in 
1888,  and  offered  it  to  the  general  public  in  1889. 
The  introduction  of  Henderson's  bean  attracted 
the  attention  of  Asa  Palmer,  of  Kennett  Square, 
Pennsylvania,  who  had  also  been  growing  a  dwarf 
Lima.  He  called  upon  Burpee,  the  well-known 
seedsman  of  Philadelphia,  described  his  variety, 
and  left  four  beans  for  trial.  These  were  planted 
in  the  test  grounds  and  were  found  to  be  valuable. 
Mr.  Palmer's  entire  stock  was  then  purchased,  — 
comprising  over  an  acre,  which  had  been  carefully 
inspected  during  the  season  —  and  Burpee  Bush 
Lima  was  presented  to  the  public  in  the  spring  of 
1890.  Mr.  Palmer's  dwarf  Lima  originated  in 
1883,  when  his  entire  crop  of  Large  White  (Pole) 
Limas  was  destroyed  by  cut-worms.  He  went 
over  his  field  to  remove  the  poles  before  fitting 
the  land  for  other  uses,  but  he  found  one  little 
plant,  about  ten  inches  high,  which  had  been  cut 
off  about  an  inch  above  the  ground  but  which  had 
re-rooted.  It  bore  three  pods,  each  containing  one 
seed.  These  three  seeds  were  planted  in  1884, 
and  two  of  the  plants  were  dwarf,  like  the  parent. 
By  discarding  all  plants  which  had  a  tendency  to 
climb,  in  succeeding  crops,  the  Burpee  Bush  Lima, 
as  we  iioav  have  it,  was  developed.  The  Kumerle, 
Thorburn,  or  Dreer,  Dwarf  Lima  originated  from 


140      HOW   DOMESTIC    VARIETIES    ORIGINATE. 

occasional  dwarf  forms  of  tlie  Challenger  Pole 
Lima,  which  J.  W.  Kumerle,  of  Newark,  New 
Jersey,  found  growing  in  his  field.  The  stock 
which  came  from  these  selected  dwarf  plants  was 
introduced  by  Thorburn  and  Dreer,  under  their 
respective  names.  The  singular  Barteldes  Bush 
Lima  came  from  Colorado,  and  is  a  similar  dwarf 
sport  of  the  old  White  Spanish  or  Dutch  Runner 
bean.  Barteldes  received  about  a  peck  of  the 
seed  and  introduced  it  sparingly.  It  attracted 
very  little  attention,  and  as  the  following  season 
was  dry,  Barteldes  himself  failed  to  get  a  crop, 
and  the  variety  was  lost  to  the  trade. 

Carinas. 

Few  plants  have  shown  more  remarkable  evolu- 
tions in  very  recent  years  than  the  cannas.  At 
the  present  time,  the  Crozy  cannas  —  so  named 
from  Crozy,  of  Lyons,  France,  who  has  introduced 
the  greater  number  of  them  —  are  most  popular. 
This  type  is  often  called  the  French  Dwarf,  or 
the  Flowering  Canna,  and  it  is  marked  by  a  com- 
paratively low  stature,  and  very  large  and  showy 
spreading  flowers  in  many  colors,  whereas  the  can- 
nas of  a  few  years  ago  were  very  tall  plants,  Avith 
small  and  late  dull  red,  narrow  flowers,  and  they 
were  grown  exclusively  for  their  foliage  effects. 
How  has  this  transformation  come  about? 


CANNAS. 


141 


In  the  first  place,  it  should  be  said  that  there 
are  many  species  of  canna,  and  about  a  half  dozen 
of  these  were  well  known  to  gardeners  at  the 
opening  of  the  century.  About  1830,  the  cannas 
began  to  attract  much  attention  from  cultivators, 
and  the  original  species  were  soon  variously  hybrid- 
ized. Crossed  seeds,  and  seeds  from  the  succes- 
sive generations  of  hybrids,  introduced  a  host  of 
new  and  variable  forms.  The  first  distinct  fash- 
ion in  cannas  seems  to  have  been  for  tall,  late- 
flowering  forms.  In  1848,  Annee,  a  cultivator  in 
France,  sowed  seeds  of  Canna  Nepalensis,  a  tall 
oriental  species,  and  there  sprung  up  a  race  of 
plants  which  has  since  been  known  as  Canna 
Annan.  It  is  probable  that  this  Canna  Nepalensis 
had  become  fertilized  with  other  species  growing 
in  Annee's  collection,  very  likely  with  Canna 
glauca.  At  any  rate,  this  race  of  cannas  became 
popular,  and  was  to  its  time  what  the  French 
dwarfs  are  to  the  present  day.  The  plants  were 
freely  introduced  into  parks,  beginning  about 
1856,  but  their  use  began  to  wane  by  1870 
or  before.  Descendants  of  this  type,  variously 
crossed  and  modified,  are  now  frequently  seen 
in  parks  and  gardens. 

The  beginning  of  the  modern  race  of  dwarf, 
laro-e-flowered  cannas  was  in  1863,  when  one  of 
the  smaller-flowered  Costa  Rican  species  (Canna 
Warscewiczii)  was  crossed  upon  a  large-flowered 


142      HOW   DOMESTIC    VARIETIES    ORIGINATE. 

Peruvian  species  (Canna  iridiflora).  The  off- 
spring of  this  union  came  to  be  called  Canna 
Ehemanni.  This  hybrid  has  been  again  variously 
crossed  with  other  species,  and  modified  by  culti- 
vation and  selection,  until  the  present  composite 
type  is  the  result.  Seeds  give  new  varieties;  and 
any  seedling  which  is  worth  saving  is  thereafter 
multiplied  by  divisions  of  the  root,  and  the  result- 
ing plants  are  introduced  to  commerce. 

These  various  examples  are  but  types  of  what 
has  been  and  can  be  accomplished  in  a  given  group 
of  plants.  There  is  nothing  mysterious  about  the 
subject,  so  far  as  the  cultivator  is  concerned.  He 
simply  sets  his  ideal,  makes  sure  that  it  does  not 
contradict  any  of  the  fundamental  laws  of  devel- 
opment of  the  plant  with  which  he  is  to  Avork, 
then  patiently  and  persistently  keeps  at  his  task. 
He  must  have  good  judgment,  skill,  and  inspira- 
tion, but  he  does  not  need  genius. 

"In  the  improvement  of  plants,"  writes  Henri 
L.  de  Vilmorin,  "the  action  of  man,  much  like 
influences  which  act  on  plants  in  the  wild  state, 
only  brings  about  slow  and  gradual  changes,  often 
scarcely  noticeable  at  first.  But  if  the  efforts 
toward  the  desired  end  be  kept  on  steadily,  the 
changes  will  soon  become  greater  and  greater,  and 
the  last  stages  of  the  improvement  will  become 
much  more  rapid  than  the  first  ones." 


LECTURE    IV. 

BORROWED  OPINIONS;  BEING  EXTRACTS  FROM 
THE  WRITINGS  OP  B.  VERLOT,  E.  A.  CARRIERE. 
AND  W.  O.  FOCKE. 

I.    Verlot's  Classification  of  Varieties  of 
Ornamental  Plants. 

Verlot  (Sur  la  Production  et  la  Fixation  des 
Varietes  dans  les  Plantes  oV  Ornement)  distributes 
the  varieties  of  ornamental  plants  into  sixteen 
groups.  I  shall  now  transcribe  these  groups,  and 
under  each  shall  give  a  very  brief  quotation  or 
abstract  of  some  of  his  remarks  concerning  them. 

1.  Varieties  distinguished  by  diminution  of  stat- 
ure, or  dwarfing.  —  Dwarfing  is  one  of  the  most 
frequent  variations  in  the  vegetable  kingdom,  but, 
unlike  many  similar  phenomena  in  the  animal 
kingdom,  these  dwarfs  are  nearly  always  very 
fertile.  If  we  question  the  cultivators  upon  the 
subject,  they  respond  that  these  variations  are 
purely  accidental,  and  that  whenever  the  varia- 
tions offer  any  reward  they  are  propagated  and 
distributed. 

Dwarfing  may  be  brought  about  by  sowing  the 
seeds  in  the  autumn  (page  115),  and  at  the  same 
143 


144  BORROWED    OPINIONS. 

time  successively  transplanting  the  plants,  as  they 
need.  Suppose,  for  example,  we  soav  seeds  of  Co- 
reopsis tinctoria  in  August  or  September.  When 
the  plants  have  developed  leaves,  the}?-  are  trans- 
planted, leaving  sufficient  space  between  them 
to  allow  of  liberal  growth.  When  the  plants 
begin  to  touch  each  other,  transplant  again,  per- 
haps three  or  even  four  times.  The  plants 
become  strong,  vigorous,  and  stocky ;  we  encour- 
age the  development  of  the  lowest  branches  and 
thereby  tend  to  shorten  the  leading  stem,  thus 
making  the  individual  comparatively  dwarf.  The 
seeds  saved  from  plants  thus  treated  during  several 
generations  will  be  more  apt  to  produce  dwarf 
varieties  than  seeds  taken  from  other  plants. 
The  greater  part  of  dwarf  varieties  appear  in 
those  plants  which  are  sown  in  autumn,  and  in 
those,  if  sown  in  spring,  which  are  submitted  to 
successive  transplantings.  Thus,  amongst  the 
annual  species  which  we  habitually  sow  in  July 
and  September,  the  following  have  produced  dwarf 
varieties  :  — 

Calceolaria  plantaginea. 

Senecio  cruentus. 

Lychnis  (or  Agrostemma)  Cceli-rosa. 

Coreopsis  (or  Calliopsis)  tinctoria. 

Oenothera  Drummondii. 

Helichrysum  bracteatum. 

Leptosiphon  densiflorus. 


veklot's  classification.  145 

Diantlms  Cliinensis. 
Scabiosa  atropurpurea. 
Schizanthus  retusus. 
Iberis  umbellata. 

Amongst  those  species  which  we  sow  in  spring, 
but  frequently  transplant,  the  following  have 
dwarf  forms  :  — 

Impatiens  Balsamina. 
Callistephus  hortensis. 
Tagetes  patula. 
Tagetes  erecta. 
Tagetes  signata. 

2.  Varieties  distinguished  by  augmentation  of 
stature,  or  giant  forms.  —  These  varieties  result 
from  various  causes,  amongst  which  are  amount 
and  fertility  of  soil,  the  employment  of  newly 
harvested  seeds,  and  crossing. 

3.  Hardy  varieties.  —  These  are  produced  by 
successive  selections  from  the  most  hardy  indi- 
viduals. Hardy  races  are  also  obtained  by  cross- 
ing with  hardy  species  or  types.  Thus,  the  forms 
of  Rhododendron  arboreum  are  rendered  hardier 
when  crossed  with  R.  Catawbiense. 

4.  Large-flowered  varieties. — These  variations 
are  always  due  to  a  good  soil  which  is  rich  in  humus, 
and  above  all  by  thorough  and  intelligent  cultiva- 
tion.    These  are  easily  fixed,  but  they  pass  away 


146  BORROWED    OPINIONS. 

insensibly  when  the  conditions  under  which  they 
were  produced  are  neglected.  This  return  to 
small  flowers  is  well  illustrated  in  the  pansy.  [All 
plants  which  are  grown  for  the  beauty  of  their 
flowers  tend  to  increase  the  size  of  those  organs, 
because  of  the  vigor  which  comes  of  good  care, 
and  the  selection  which  necessarily  follows.  The 
frequency  of  the  varietal  name  "grandiflora"  is 
proof  of  this.  As  soon  as  the  plant  has  made  «ny 
perceptible  gain  in  the  size  of  its  flowers,  some 
nurseryman  adds  this  adjective  to  its  name,  as  in 
Hydrangea  paniculata  grandiflora.  No  doubt  the 
name  is  sometimes  bestowed  without  warrant,  for 
the  purpose  of  selling  the  plant.  Frequently  the 
catalogue-maker  drops  the  proper  specific  name 
and  uses  the  varietal  adjective  as  if  it  were  the 
legitimate  name  of  the  plant,  as  in  Gazania  grandi- 
flora, which  is  properly  Gazania  rigens,  variety 
grandiflora.] 

5,  6.  Early  and  late  varieties.  —  The  chief 
agency  affecting  the  duration  of  plants  is  climate, 
and  desired  variations  in  earliness  or  lateness  are 
obtained  by  transporting  the  plants  to  those  cli- 
mates which  produce  such  effects  as  we  seek,  and 
growing  them  there  for  a  time  ;  or  we  can  procure 
seeds  from  such  climates,  if  the  given  plants  are 
already  grown  there. 

The  age  of  the  seed  also  has  an  influence  upon 
the  resulting  individual :  the  fresher  the  seed,  the 


veelot's  classification.  147 

more  rapid  its  germination,  and  consequently  the 
more  prompt  the  development  of  the  plant.  We 
have  reason  to  expect  that  fresh  seeds  will  have  a 
tendency  to  produce  early  varieties,  and  that,  on 
the  contrary,  old  seeds,  by  germinating  more 
slowly,  will  produce  variations  more  or  less  late. 
[Not  only  does  the  age  of  the  seed  seem  to  be 
important  in  this  connection,  but  recent  experi- 
ments seem  to  show  that  the  degree  of  maturity 
also  modifies  the  offspring.  Seeds  which  are 
barely  ripe  enough  to  germinate  have  a  tendency 
to  give  earlier  progeny  than  those  which  are  fully 
matured  and  ripened.     See  page  103.] 

The  first  seeds  to  mature  on  any  plant  may  be 
expected  to  give  early  plants,  and  the  subsequent 
seeds  give  later  plants.  [Verlot  states  that  a  cold 
region  tends  to  make  the  plants  later  when  trans- 
ferred to  it,  but  this  seems  to  be  an  error.  The 
fact  is  generally  just  the  reverse.  Plants  taken 
towards  the  poles  or  to  higher  altitudes,  become 
earlier  in  two  ways,  by  shortening  their  period 
of  growth,  and  by  vegetating  at  a  less  sum- 
temperature  in  spring.     See  page  26.] 

7.  Odoriferous  varieties.  —  Odor  varies  greatly, 
even  amongst  varieties  of  one  species.  The  causes 
of  the  differences  in  fragrance  are  not  numerous 
and  they  are  little  understood.  Climate,  exposure, 
and  the  nature  of  the  soil  are  leading  factors. 
The  odor  of  plants  which  grow  on  dry  and  arid 


148  BORROWED   OPINIONS. 

hills  is  much  more  penetrating  than  that  of  the 
same  species  cultivated  in  humid  and  shady  places. 
It  is  possible,  even,  to  entirely  change  the  odor  by 
transporting  the  plant  from  one  place  to  another. 
For  example,  Satyrium  hircinum  exhales  a  most 
pronounced  goat-like  odor  in  the  vicinity  of  Paris 
and  northward,  whilst  in  the  east,  and  particularly 
in  the  southern  regions,  its  flowers  have  an  odor 
which  is  somewhat  like  that  of  vanilla. 

8.  Varieties  ivith  colored  parts. — Coloration  may 
be  either  complete  or  partial,  and  it  may  reside 
in  any  or  all  parts  of  the  plant,  as  follows :  — 

The  stems. 
The  leaves. 

The  flowers,  j  varf/f ed- 
(  spotted. 

The  fruits. 
The  seeds. 

Variations  in  color  are  the  most  frequent  of  all 
modifications  in  cultivated  plants.  These  depart- 
ures may  be  expected  to  arise  under  the  influence 
of  continued  cultivation  and  repeated  sowings; 
and  the  variations  must  then  be  selected  until 
they  are  fixed. 

9.  Varieties  without  color,  or  albinos. — Partial 
albinism,  or  variegation,  is  as  frequently  observed 
in  spontaneous  plants  as  it  is  in  cultivated  ones. 
It  usually  occurs  in  the  leaves  only,  but  it  is  some- 


verlot's  classification.  149 

times  a  feature  of  the  entire  plant.  A  variegated 
plant  does  not  exist  of  which  we  do  not  know  the 
non- variegated  type.  These  variegated  plants 
appear  both  from  seeds  and  from  bud-variations, 
and  they  are  most  surely  propagated  in  the  latter 
case.  It  has  been  said  that  when  the  albinism 
affects  the  margin  of  the  leaf  it  is  more  likely  to 
be  transmitted  than  when  it  occupies  the  central 
part  of  the  blade,  but  this  generalization  has  many 
exceptions.     Page  157. 

It  is  a  curious  fact  that  variegation  and  double- 
ness  of  flowers  are  generally  antagonistic,  for  they 
do  not  appear  in  the  same  plant.  One  excludes 
the  other.  It  is  supposed  by  Morren  [and  gen- 
erally accepted]  that  doubling  is  the  result  of 
excessive  vigor  and  that  partial  albinism  comes 
of  an  enfeebling  of  the  vital  functions. 

Variegations  sometimes  disappear  entirely  and 
then,  after  two  or  three  years,  reappear  in  the 
same  individual.  The  first  leaves  of  seedlings 
from  variegated  plants  may  be  perfectly  green, 
and  the  seedlings  may  afterwards  take  on  the  varie- 
gated character.  This  behavior  is  well  marked 
in  some  ferns. 

Complete  albinism,  or  chlorosis,  indicates  a  pro- 
found alteration  in  the  tissues,  and  it  is  impossi- 
ble of  propagation.  This  decoloration  is  most 
commonly  a  bud- variation. 

10.    Double   varieties,   or  those   distinguished  by 


150  BORROWED   OPINIONS. 

the  transformation  of  the  sta?7iens  and  pistils  into 
petaloid  organs  —  There  are  various  degrees  of 
doubling  or  duplication  in  flowers.  The  calyx 
and  corolla  alone  may  be  duplicated,  in  which 
case  the  flower  is  still  fertile.  Sometimes  the  sta- 
mens only  are  transformed  into  petal-like  organs, 
and  the  flower  is  then  fertile  if  pollen  is  trans- 
ferred from  another  flower.  Sometimes  all  the 
floral  series  —  calyx,  corolla,  stamens,  pistils  — 
may  be  duplicated  or  transformed  ;  then  we  have 
a  full  (pleine)  flower,  which  is  incapable  of  pro- 
ducing seeds  or  of  fecundating  another  flower. 
[Annual  plants,  and  others  not  propagated  by 
buds  and  other  asexual  parts,  which  bear  full 
double  flowers,  must  be  propagated  by  seeds  taken 
from  flowers  which  are  nearly  full  double,  but 
which  bear  a  few  seeds ;  or,  sometimes  from  a 
nearly  single  flower  which  is  fertilized  by  pollen 
from  a  nearly  full  double  flower.  In  these  cases, 
it  is  unusual  for  all  the  seedlings  to  produce  full 
double  flowers.] 

A  rich  soil,  a  cultivation  which  produces  a  luxu- 
riant vegetation,  are  the  conditions  which  gen- 
erally produce  doubling  in  flowers.  But  we  can 
repeat  with  De  Candolle,  "  That  if  we  are  gen- 
erally ignorant  of  the  causes  of  the  doubling  of 
flowers,  Ave  also  know  that  if  we  gather  seeds 
from  an  individual  with  semi-double  flowers,  the 
plants  which  result  have  a  greater  tendency  to  pro- 


verlot's  classification.  151 

cluce  double  flowers  than  seeds  taken  from  simple 
flowers." 

Doubling  may  occur  in  all  plants,  whether  an- 
nuals, biennials,  herbaceous  or  woody  perennials, 
and  in  all  of  them,  when  they  are  fertile,  we  can 
finally  make  them  reproduce  the  character  iden- 
tically. 

We  must  always  choose  for  seed-parents  the 
individuals  of  which  the  flowers  are  very  double, 
and  exclude  with  the  greatest  care  the  single- 
flowered  plants,  which  are  the  most  fertile  and 
the  progeny  of  which  quickly  smother  the  progeny 
of  the  double  flowers. 

11.  Proliferous  varieties.  —  [These  are  varia- 
tions which  are  characterized  by  growths  arising 
from  unusual  places,  as  one  flower  springing  out 
of  another  flower,  a  branch  or  rosette  growing  out 
of  a  flower,  an  unusual  production  of  bulbs  or 
young  plants  from  the  root,  bulbs  from  leaves  or 
the  fronds  of  ferns,  and  the  like.]  These  forms 
are  infrequent  in  cultivated  plants  and  very  rare 
amongst  wild  plants.  They  are  generally  asso- 
ciated with  the  fertility  of  the  soil.  The  pro- 
liferous form  of  Papaver  somniferum  known  as 
Papaver  monstruosum,  perpetuates  itself  per- 
fectly by  seeds,  but  these  variations  are  usually 
unstable. 

12.  Varieties  ivith  conjoined  parts  (yariStSs  par 
soudures). —  We  know  of  a  single  example  of  this 


152  BORROWED    OPINIONS. 

monstrosity  in  ornamental  plants  :  it  is  that  of 
Papaver  bracteatnm,  in  which  the  corolla  has 
become  monopetalous  by  the  growing  together  of 
the  petals.  This  monstrosity  (described  and  fig- 
ured in  Revue  Horticole)  is  cultivated  by  Vilmorin. 
They  can  propagate  it  only  by  cuttings.  They 
have  tried  in  vain  to  multiply  it  by  seeds.  [Simi- 
lar forms  of  other  species  are  known.] 

12.  Abortive  varieties.  — This  type  of  monstros- 
ity, which  constitutes  one  of  the  most  interesting 
chapters  in  vegetable  teratology,  has  been  ob- 
served in  all  parts  of  the  flower.  They  are  mal- 
formations which  have  no  interest  from  the  point 
of  view  of  ornament.  [The  petals,  or  other  or- 
gans, sometimes  almost  entirely  disappear  in  this 
type  of  variations.] 

11.  Peloric  varieties.  —  [Peloria  is  a  name  ap- 
plied by  Linnaeus  to  a  form  of  the  toad-flax,  Lina- 
ria  vulgaris,  in  which  all  of  the  five  petals  have 
spurs,  while  the  normal  form  has  only  one  petal 
spurred.  The  term  is  now  applied  generically  to 
all  similar  regularity  of  structure  in  normally  ir- 
regular flowers.]  The  causes  which  produce  tins 
transformation  are  not  known,  but  aridity  and  dry- 
ness of  the  soil,  and  new  conditions  of  vegetation, 
appear  to  favor  its  development.  These  mon- 
strosities, at  least  in  linaria,  are  propagated  easily 
by  cuttings  or  buds,  and  Willdenow  records  an 
experiment  in  which  they  came  true  from  seeds. 


VERLOT'S    CLASSIFICATION*  153 

15.  Chloranthic  varieties.  —  Here  are  included, 
in  a  general  way  and  in  lieu  of  a  better  name,  all 
those  transformations  which  render  the  flowers 
absolutely  sterile,  and  transform  them  more  or 
less  completely  into  branches  or  leaf -like  organs. 
They  are  purely  bud- variations,  and  can  be  per- 
petuated only  by  cuttings,  buds,  or  other  asexual 
parts. 

16.  Various  or  polymorphous  varieties,  compris- 
ing the  following  types  :  — 

thornless, 
spineless, 
Stems  \  f astigiate, 
filiform, 
weeping,  etc. 
f  crisped, 
T  J  fasciated, 

bullate  or  blistered, 
laciniate,  etc. 

The  various  modifications  originate  both  by 
seed-variation  and  bud-variation. 


II.    Carriere's  Account  of  Bud-Varieties. 

The  subject  of  bud-variations  or  sports  never 
fails  to  interest  the  student,  and  however  familiar 
he  may  be  with  these  forms  he   never  ceases  to 


154  BORROWED    OPINIONS. 

wonder  at  them.  I  have  taken  pains,  therefore, 
in  addition  to  what  I  have  already  said  upon  the 
subject  (see  pages  28,  117),  to  translate  almost 
bodily  Carriere's  account  of  bud-varieties  (in  Pro- 
duction et  Fixation  des  Varietes  dans  les  Veye- 
taux),  because,  although  written  in  1865,  it  is 
the  most  extended  list  of  bud-varieties  which  I 
know.  The  catalogue  might  be  greatly  extended 
by  inserting  the  current  varieties  in  commerce  in 
this  country,  but  the  original  list  is  sufficiently 
full  for  all  purposes  of  illustration.  Carriere's 
account  now  follows  :  — 

1.    General  Remarks  upon  Bud- Variation. 

Plants  being  composed  of  a  certain  number  of 
elements  disposed  in  a  certain  order,  and,  more- 
over, these  elements,  under  the  influence  of  organic 
laws,  being  able  to  separate  or  group  themselves 
in  different  ways,  it  follows  that  the  same  plant 
can,  upon  its  different  parts,  present  characters 
and  properties  more  or  less  different  from  those 
which  it  normally  presents.  It  is  this  fact  which 
constitutes  that  which  in  practice  we  call  an  acci- 
dent [or  bud  variety],  either  of  dimorphism1  [of 
form]  or  of  dichroism  [of  color]. 

1  French  writers  use  the  word  accident  in  the  sense  in  which 
we  use  bud-variation.  The  word  dimorphism,  used  by  Car- 
riere  for  one  of  the  features  of  bud- variation,  is  now  applied  to 


carriere's  remarks  on  bud- variation.    155 

We  refer  to  bud-variation  the  phenomenon, 
whose  cause  is  unknown,  which  allows  a  bud  on 
any  part  of  the  plant  to  develop  a  member  whose 
form  and  appearance  differ  from  those  borne  on 
other  parts  of  the  plant.  Thus  the  common  beech 
producing  a  branch  with  laciniate  leaves,  Podocar- 
pus  Koraiana  producing  a  branch  whose  ramifi- 
cations are  whorled  and  spreading  instead  of  being 
scattered,  and  Avhose  leaves  are  distichous  instead 
of  being  alternately  disposed  about  the  branches 
as  they  are  normally,  are  examples  of  bud-varie- 
ties. 

Taken  in  its  most  absolute  sense  and  considered 
in  the  sum  of  all  its  characters,  bud- variation,  aside 
from  the  details  which  it  presents,  can  be  divided 
into  two  sections  :  one  which  includes  all  the  phe- 
nomena which  are  manifested  suddenly,  as  in  the 
case  of  the  fern-leaved  beech,  the  hemp-leaved 
rose,  the  English  willow -leaved  cherry,  sour 
grapes  Avith  long  seeds,  etc.;  the  other  includes 
all  slower  transformations,  as  in  the  case  of  Rosa 
Eglanteria,  tulips,  Iris  Xiphium,  Viola  Rotho- 
magensis,  var.  pallida,  etc.  Strictly,  we  could 
establish  a  third  section  to  include  all  the  trans- 
formations resulting  from  the  age  of  the  individ- 

different  permanent  and  characteristic  forms  of  individuals  of 
the  same  species.  It  is  most  commonly  observed  in  the  different 
relative  lengths  of  stamens  and  pistils.  I  have  substituted  other 
words  for  it  in  most  places  in  the  text.  —  L.  H.  B. 


156  BORROWED    OPINIONS. 

ual,  which  are  the  consequences  of  its  aclultness. 
HoAvever,  this  last  series  of  phenomena  is  seen 
only  in  polymorphous  species,  which  change  in 
appearance,  form,  and  nature  when  they  grow  old 
and  especially  when  they  bear  fruit ;  such  are  the 
ivies,  Ficus  stipulata  or  scandens,  eucalyptus,  etc. 
Horticulture  often  profits  by  this  peculiar  prop- 
erty of  plants ;  multiplying  separately  the  parts 
with  the  exceptional  characters,  it  obtains  individ- 
uals which  present  an  appearance  different  from 
the  plants  from  which  they  arise.  [This  dissimi- 
larity between  young  and  mature  individuals  of 
the  same  species  is  well  marked  in  some  of  the 
Conifera3,  as  the  cedars  and  retinosporas.] 

In  a  general  way,  then,  dimorphism  refers  to 
a  different  form  on  the  same  individual,  whether 
the  change  be  complete  or  partial.  Dichroism  is 
exactly  analogous  to  it  in  essential  points,  only 
that  it  refers  to  color  instead  of  to  form.  Thus, 
Flon's  Pink  [Dianthus  semperflorens  of  gardens, 
introduced  by  M.  Flon  of  Angers],  which  has  red 
flowers,  developing  a  branch  similar  to  the  plant 
in  aspect  and  form,  but  bearing  white  flowers, 
the  ovate -leaved  privet  and  the  Japanese  fusain 
[Euonymus  Japonicus]  producing  buds  giving 
rise  to  variegated  leaves,  white  kidney-beans  pro- 
ducing black  ones,  and  vice  versa,  are  examples  of 
dichroism. 

Let  us  say  that  in  bud-variation,  less  than  any- 


CARRIEKE   ON   BUD-VARIATION.  157 

where  else,  we  can  do  nothing  towards  obtaining 
or  producing  the  variations.  Bud-varieties  most 
often  spring  up  spontaneously,  so  to  speak,  and  in 
this  respect  our  work  is  purely  passive,  consisting 
in  superintending  these  digressions  or  accidents 
in  the  endeavor  to  take  advantage  of  them  when 
they  are  presented.  Let  us  state,  also,  that  in 
these  series  of  varieties  we  find  a  considerable 
diversity,  either  in  the  habit  or  aspect  of  the 
plants  or  in  their  foliage  or  flowers,  or  sometimes 
even  in  their  fruits,  and  that  we  oftener  find  vari- 
egations than  among  plants  which  come  from  seeds. 
We  ought  to  recall  just  here, — what  we  have 
said  on  the  subject  of  plants  issuing  from  seeds, — 
that  variegations  are  the  more  constant  the  more 
completely  they  circumscribe  the  organs  upon 
which  they  occur,  whether  upon  the  flowers  or  the 
leaves ;  also,  that  when,  on  a  plant  whose  variega- 
tions are  disposed  in  stripes  or  bands,  we  find  a 
part  upon  which  they  are  disposed  circularly,  we 
can  be  almost  certain  that,  if  we  detach  and  graft 
or  make  a  cutting  of  this  part,  we  shall  preserve 
its  new  character.  This  phenomenon  is  very  fre- 
quent in  the  camellias  and  especially  in  the  azaleas. 
The  greater  part  of  the  varieties  of  azalea  which 
present  these  characters  have  had  no  other  origin.1 

1  To  preserve  variegations,  it  is  best  to  resort  to  graftage, 
generally  speaking,  as  cuttings  tend  to  produce  individuals 
mure  vigorous,  and  winch  therefore  tend  to  return  to  the  green 


158  BORPOWED    OPINIONS. 

Certain  species  are  much  more  disposed  than 
others  to  produce  these  bud-varieties,  either  of 
dimorphism  or  dichroism.  We  give  an  example 
from  the  Chinese  chrysanthemum.  About  188(3, 
the  horticultural  establishment  of  Fromont  re- 
ceived from  England  three  varieties  of  this 
chrysanthemum;  one  had  the  flowers  red,  one 
variegated,  and  one  white  flesh-colored.  Planted 
in  the  open  air,  the  following  year  we  saw  the 
three  varieties  on  one  plant,  which  seems  to 
show  that  these  three  varieties  were  only  sports 
from  a  common  form.  A  phenomenon  analogous 
to  the  preceding,  and  which,  like  it,  concerns  the 
Chinese  chrysanthemum,  was  shown  at  the  Mu- 
seum1 in  1856  upon  a  variety  called  Surprise. 
This,  which  bore  flowers  scarcely  rose  flesh-col- 
ored, produced,  on  one  of  its  branches,  flowers  of 
a  deep  rose-lilac.  Cuttings  having  been  made, 
it  has  preserved  all  its  characters,  and  to-day  it 
is  still  one  of  the  most  beautiful  of  the  section. 
We  call  it  Gain  du  Museum.  In  1862,  upon  this 
same  Gain  du  Museum,  a  branch  developed  which 
bore  flowers  perfectly  white,  of  almost  the  same 
size  and  form  as  those  of  the  type;  then  upon  dif- 

color,  or  even  to  the  normal  form,  if  the  variety  differs  also  in 
form.  We  must  select  the  parts,  in  perpetuating  variegations, 
in  which  the  variegation  is  very  pronounced,  although  we  must 
exercise  care  that  the  variegation  be  not  too  intense,  else  the 
offspring  will  be  weak  and  poor.  — Carkieke.  (See  page  149.) 
1  Museum  d'llistoire  Naturelle  de  Paris. 


.CARRIERE   ON   BUD-VARIATION.  159 

ferent  branches  beside  it  were  found  others  bear- 
ing flowers  half  red,  half  white.  In  making  cut- 
tings from  these  two  kinds  of  branches,  we  would 
then  obtain  from  the  Surprise  still  other  varieties. 
Let  us  look  at  the  variety  Sophie.  This,  which 
has  dirty  white  flowers  very  slightly  tinged  with 
red,  with  yellow  centre,  has  produced,  by  bud- 
variation,  a  plant  known  as  Trophee.  The  latter, 
which  has  flowers  of  a  rose-lilac-violet,  bears  some 
resemblance  to  the  Gain  du  Museum.  There 
were  also  upon  the  same  branch,  but  on  different 
twigs,  flowers  similar  to  those  borne  by  the  varie- 
ties Trophee  and  Sophie.  These  new  flowers 
were  flat  and  had  narrow  and  imbricated  petals, 
whilst  the  Trophee  has  convex  flowers,  large  and 
slightly  serrate  petals.  The  Madame  Richard 
chrysanthemum,  of  which  the  flowers  are  whitish 
very  lightly  bordered  with  rose,  has  produced  on 
one  of  its  branches  violet  flowers  stronger  than 
those  of  the  plant  from  which  it  sprung;  the 
petals  are  also  larger  and  more  imbricated.  In 
1863  Ave  observed  on  certain  varieties  of  chrysan- 
themum the  following  sports:  the  variety  called 
Ceclo  nulli,  with  double  white  flowers  very  lightly 
rose,  produced  a  branch  which  bore  flowers  much 
larger  and  much  more  spreading  than  those  of 
Cedo  nulli.  The  Argentine,  with  small  white 
flowers,  pompon-form,  gave  a  branch  more  vigor- 
ous than  itself,  whose  spreading,  very  large  flow- 


160  BORROWED   OPINIONS. 

ers,  of  a  beautiful  yellow,  resembled  to  a  certain 
extent  those  of  the  large-flowered  chrysanthemum, 
a  fact  which  tends  to  show  that  from  the  pompons 
to  the  large-flowered  sorts  there  is  but  a  step.  In 
1864  we  saw  upon  a  stem  of  the  Vesta  (a  pompon 
chrysanthemum  which  has  white  flowers)  several 
branches  which  bore  flowers  entirely  deep  yellow. 
The  dimensions,  as  well  as  the  form  of  the 
flowers,  were  the  same. 

Varieties  obtained  by  bud-variation  are  very 
numerous.  There  is  not  a  genus  among  those 
which  comprise  a  number  of  species  which  has 
not  produced  them.  Although  we  shall  mention, 
farther  on,  a  certain  number  of  these  bud-varie- 
ties, adding  some  observations,  there  are  some 
which,  in  our  opinion,  are  so  interesting  that,  by 
anticipation,  we  ought  to  speak  of  them  here. 
One  of  them  relates  to  a  kind  of  pink  which  is 
known  in  commerce  as  Flon's  pink.  This  Flon's 
pink,  which  is  closely  related  to  those  which  we 
call  Spanish  pink,  Badin  pink,  etc.,  has  flowers 
very  deep  red,  almost  double,  so  that  it  does  not 
produce  seeds,  and  we  are  obliged  to  multiply  it 
by  cuttings.  Nevertheless,  it  has  already  given, 
by  bud-variation,  several  varieties,  of  which  the 
most  remarkable,  a  very  beautiful  white,  was  de- 
veloped in  1858.  Since  that  time  this  variety 
has  been  maintained  with  all  its  characters.  Ob- 
tained by  M.   Pare,  horticulturist  at   Paris,  this 


CARRIEUE    ON   ROSE   SPORTS.  161 

variety  has  been  called  Marie  Pare,  for  one  of 
the  children  of  the  originator.  Other  varieties, 
presenting  colors  different  from  that  of  which  we 
have  spoken,  have  been  developed  from  Flon's 
pink  by  M.  Pare.  [The  pinks  are  fertile  in  bud- 
varieties,  particularly  the  carnation.  Many  of 
the  carnations  which  are  now  well  known  to  com- 
mercial growers  first  appeared  as  sports.  The 
Portia,  which  is  a  deep  self -red,  frequently  sports, 
sometimes  into  almost  pure  white.] 

The  genus  which,  probably,  has  produced  the 
most  examples  of  this  nature  is  the  Rose.  The 
examples  are  so  very  interesting  that  we  cannot 
resist  the  temptation  to  say  something  in  detail 
concerning  them.  We  will  cite  several  remark- 
able examples,  commencing  with  those  which 
have  sprung  from  the  Hundred-leaved  Rose  [Pro- 
vence rose,  Rosa  centifolia].  The  bud-varieties 
which  have  issued  from  this  rose  can  be  arranged 
in  two  series :  one  which  includes  all  individuals 
which  are  but  little  removed  from  the  type,  which 
differ  from  it  only  in  color  or  form,  either  of  the 
flowers  or  sometimes  of  the  leaves,  and  comprise 
the  ordinary  Hundred-leaved  roses;  the  other 
series  includes  individuals  possessing  the  charac- 
ters of  the  first  series,  but  which,  in  addition,  are 
provided  with  small  bracts  or  glandular  hairs 
which  give  the  name  "Moss-rose."  Bud-varieties 
produced  by  Rosa  centifolia  :  — 


162  BORROWED    OPINIONS. 

A.  Ordinary  Hundred-leaved  roses. 

I.  Flowers  more  or  less  large. 

Cabbage-leaved  or  lettuce-leaved  B.  cen- 

tifolia. 
Celery-leaved. 
Anemone. 
Nancy. 
Peintres. 

Flore  magno,  or  Foliaceous. 
Apetalous. 
Unique  white. 
Unique  variegated. 

II.  Flowers  small.  —  Pompons. 

Burgogne  pompon. 
White  pompon. 
Bordeaux  pompon. 
Kingston  pompon. 

B.  Moss-roses. 

I.  Flowers  more  or  less  large. 

Ordinary. 

Cristata. 

White-flowered 

Variegated. 

Sage-leaved. 

Unique  Provence. 

Zoe,  or  Mousseuse  partout. 

II.  Flowers  small.  — Pompons. 

Pompon. 


CABEIEBE   ON    ROSE    SPORTS.  163 

One  must  not  suppose  that  all  the  moss-roses 
which  he  meets  with  to-day  in  commerce  are  the 
result  of  bud- variation.  The  larger  part,  on  the 
contrary,  come  from  seeds.  The  moss-rose  is 
nearly  a  race.  From  seeds  taken  from  the  moss- 
rose,  we  have  obtained  a  certain  number  of 
individuals  which  have  preserved  the  general 
characters  of  the  plants  from  which  they  came  ; 
they  are  more  or  less  " mossy."  Let  us  state, 
however,  that  this  "mossy"  character  is  not  pecu- 
liar to  any  section  of  roses,  but  that  we  find  it 
in  most  garden  species,  as  the  hybrid  remontants, 
rose-of-four-seasons,  etc.  The  fact  of  the  repro- 
duction of  the  "  mossiness "  of  roses  by  seeds, 
proves  again,  what  we  have  asserted  several  times, 
that  everything  in  a  plant  tends  to  reproduce 
itself,  that  the  peculiarities,  properties,  monstrosi- 
ties even,  may  become  hereditary. 

The  Zoe  moss-rose  is  one  of  the  most  remark- 
able bud-varieties  which  has  been  produced  by 
Rosa  centifolia.  This  variety,  instead  of  being 
"  mossy "  only  upon  the  peduncle  or  calyx,  as 
most  of  the  other  varieties  of  this  group  are, 
is  "mossy"  on  all  its  parts,  whence  the  name 
Mousseuse  part  out,  ["mossy  everywhere  "].  This 
variety  was  produced  again  in  1864,  at  M.  Ja- 
main's,  horticulturist,  Paris,  where  we  followed 
the  development  of  it.  We  also  learned  that  at 
this    place,   in    two    beds    planted    with   ordinary 


164  BORROWED    OPINIONS. 

moss-roses,  beside  the  Zoe,  there  were  several 
stems  which  tended  likewise  to  modify  them- 
selves, some  in  their  leaves,  others  in  their 
flowers. 

We  must  remark  that  it  often  happens  that 
certain  individuals  of  bud-varieties  return,  on 
some  one  of  their  parts,  to  the  type  from  which 
they  came.  Thus,  on  a  moss-rose  from  R.  cen- 
tifolia,  we  have  seen  a  branch  of  the  ordinary 
Hundred-leaved  rose.  We  should  observe,  how- 
ever, that  most  usually  the  parts  which  seem  to 
return  to  the  type  present,  notwithstanding,  differ- 
ences from  it.  There  has  been  a  step  in  advance, 
and  it  is  contrary  to  nature  to  retrace  completely. 

The  Rose  du  Roi,  known  by  nearly  every  one, 
has  produced  the  following  six  bud-varieties :  — 

1.  Bernard  Perpetual.  This  rose  has  the 
branches  more  slender  than  those  of  the  parent; 
its  flowers  and  leaves  are  also  smaller.  Its  pom- 
pon flowers  are  very  pretty,  with  a  rose-color  very 
much  brighter  than  that  of  the  Rose  du  Roi. 

2.  Long-peduncled  Rose  du  Roi.  This  has 
branches  much  longer  than  those  of  the  type  ; 
the  internodes  are  more  distant,  and  the  peduncles 
are  also  longer.     It  is  only  a  sort  of  degeneration. 

3.  Madame  Tellier.  Very  similar  to  the  last, 
being  distinguished  only  by  its  flowers,  which  are 
less  colored,  possessing  a  very  bright  rose  flesh- 
color. 


CARRIERE   ON   ROSE   SPORTS.  165 

4.  Mosrador.  This  rose  differs  from  Rose  du 
Roi  by  its  stronger  flowers,  of  a  more  vivid,  deeper 
red  ;  its  branches  more  colored,  permitting  it  to 
be  distinguished  even  in  winter.  Horticulturists 
do  not  like  this  variety,  because  it  is  hard  to 
force,  and  because  it  passes  very  quickly  to  a 
dirty  violet. 

5.  Capitaine  Renard,  or  Variegated  Rose  du 
Roi.  This  variety  differs  from  Madame  Tellier 
by  its  flowers  being  variegated  or  ribboned  with 
Avhite.  It  was  found  at  Orleans  by  M.  Desfosse- 
Thuillier. 

6.  Ccelina  Dubos.  Found  by  M.  Dubos,  hor- 
ticulturist at  Pierrefitte,  near  Saint-Denis,  upon 
Rose  du  Roi.  It  has  the  branches  more  slender 
and  the  leaves  a  little  smaller  than  the  parent ; 
its  flowers,  very  similar  in  form  to  those  of  the 
type,  are  white,  slightly  flesh-colored. 

The  Rose  de  la  Reine  has  produced  two  sports : 
one,  Belle  Normancle,  whose  flowers,  rose  flesh- 
colored,  recall  those  of  Souvenir  de  la  Malmaison; 
the  other,  Madame  Cambel  of  Isly,  or  Triomphe 
de  Valenciennes,  which  differs  from  the  parent 
only  in  its  marbled-variegated  flowers. 

The  Duchesse  de  Cambaceres  rose,  which  has 
uni-colored,  deep  rose  flowers,  has  produced  by 
bud-variation  Belle  de  Printemps,  which  has  rose 
flowers  marbled  with  brown. 

The    Baronne    Prevost    has   produced,    to    our 


166  BORHOAVED    OPINIONS. 

knowledge,  five  varieties,  two  of  which  have 
variegated  flowers  and  one  marbled.  One  of  the 
two  variegated  varieties,  Madame  Desiree  Girand, 
was  found  at  the  place  of  M.  Desire  Girand  at 
Marly,  near  Valenciennes.  It  is  not  vigorous. 
The  second  variety,  Panachee  d'Orleans,  which 
was  observed  for  the  first  time  at  Orleans,  is 
very  vigorous.  Its  branches  are  more  slender 
than  those  of  Baronne  Prevost,  and  the  very 
smooth  and  shiny  bark  has  few  prickles.  In 
short,  its  branches  recall  those  of  Cnisse  de 
Nymphe.  It  sometimes  happens  that  this  variety 
produces  large  branches,  vigorous  and  very  thorny, 
but  less  so  than  those  of  Baronne  Prevost ;  its 
flowers  also  resemble  the  type  more  closely.  It  is 
an  intermediate  produced  by  the  single  matter  of 
vegetation.  The  Baronne  Prevost  marbre  dif- 
fers from  the  type  only  in  its  flowers,  which  are 
marbled  with  brown.  Another  variety,  placed 
in  the  trade  by  M.  Pierre  Oger,  horticulturist 
at  Caen,  differs  from  the  type  only  in  the  color 
of  the  flowers,  which  are  very  much  paler.  The 
fifth  sport  produced  by  the  Baronne  Prevost  is 
more  recent.  We  observed  it  first  in  1864,  at 
Vitry-sur-Seine,  in  a  garden  under  the  care  of 
M.  Lachaume.  We  called  it  Madame  Lachaume. 
It  differs  from  the  type  by  its  branches  being  a 
little  less  thorny,  but  especially  by  its  inflores- 
cence, which,  long-paniculate,  very  much  branched, 


CARRIERE   ON   ROSE   SPORTS.  167 

recalls  that  of  certain  Noisettes.  The  flower,  also, 
is  a  little  Aveaker  than  that  of  the  type.  But  a 
very  remarkable  fact  is  that  the  hip,  instead  of 
being  very  regularly  attenuated  at  its  base  and 
becoming  confounded  with  the  peduncle,  as  in 
Baronne  Prevost,  is  abruptly  and  slightly  in- 
flated, then  contracted,  and  inflated  again  near 
the  summit.  The  peduncles  are  also  much  more 
slender  and  longer  than  those  of  the  parent. 

The  Duchesse  d' Orleans,  whose  flowers  are 
violet-rose,  produced  by  bud-variation,  in  1858,  a 
variety  known  as  Soeur  des  Anges.  This  variety 
differs  from  its  parent  particularly  in  the  color  of 
the  flowers,  which  is  pale  flesh-rose,  like  that  of 
the  flowers  of  Souvenir  de  la  Malmaison. 

The  rose  called  Quatre-Saisons  has  produced 
the  following  sports  :  — 

1.  White  Moss,  or  de  Thionville.  This  was 
first  observed  at  Thionville  about  18-35.  It  dif- 
fers from  the  type  by  its  branches  being  more 
slender  and  supplied  with  hispid,  glandular  hairs. 
Its  light  green  leaves  are  also  softer  to  the  touch 
and  slightly  tomentosc.  Its  flowers  are  pure 
white.  Sometimes  it  produces  strong  branches 
which  bear  rose-colored  flowers.  In  this  latter 
condition  it  is  the  ordinary  Quatre-Saisons,  a  fact 
observed  by  M.  Duval  of  Montmorency,  later  by 
M.  Victor  Verdier,  Paris,  and  recently  (1864)  at 
the  Museum. 


168  BORROWED   OPINIONS. 

2.  Quatre-Saisons  pompon. 

3.  White. 

The  Provence  roses  have  likewise  produced  a 

number  of  bud-varieties.     Among  the  best  known 

are :  — 

Pompon  Saint-FranQois. 

Pompon  Saint-Jacques. 

Camaieu. 

Panache  semi-double. 

Tricolore  de  Flandre. 

The  last  variety,  which  appeared  in  Belgium 
some  years  ago,  is  remarkable  for  its  variegated 
floAvers ;  it  is  a  slender  grower,  although  it  comes 
from  a  very  vigorous  variety.  It  sometimes  re- 
turns to  the  type.  The  variety  Camaieu  is  remark- 
able for  its  striped  flowers,  very  pretty,  and  al- 
most unique  in  the  genus.  Its  wood  is  meagre 
and  its  leaflets  are  toothed. 

In  the  Damask  roses,  which  are  sorts  of  Quatre- 
Saisons  roses,  not  remontants,  we  consider  as  bud- 
varieties  the  three  following  :  — 

Damask  York  and  Lancaster. 
Damask  with  blistered  leaves. 

The  ordinary  Bengal  rose  has  sported  into  the 
Bengale  a  bois  strie  [striped-stemmed  Bengal]. 
The  branches  are  often  almost  completely  yellow. 

A  very  curious  sport  of  the  rose  is  the  plant 
which  we  have  called  Rosier  a  feuilles  de  Chanvre 


BUD-VAUIATION   IN   THE   UOSE.  169 

[hemp-leaved  rose] .  By  its  flowers  and  especially 
by  its  leaves,  this  variety  differs  considerably  from 
Rosa  alba,  from  which  it  comes.  Its  leaflets  are 
hooded,  long  and  narrow,  and  very  coarsely  den- 
tate-serrate, sometimes  as  if  gnawed  on  the  edges, 
strongly  nerved,  of  a  dark  green,  rugose-scabrous. 
It  happens  sometimes,  also,  that  its  leaves  are 
opposite  upon  certain  branches.  The  flowers  of 
this  variety  are  smaller  than  those  of  Rosa  alba, 
often  irregular,  and  somewhat  monstrous,  and 
always  sterile.  [Probably  no  plants  are  so  prolific 
of  bud-varieties  as  the  roses.  Every  gardener  of 
experience  has  observed  the  fact.  The  follow- 
ing experiences  of  a  single  horticulturist  (Ernest 
Walker,  New  Albany,  Indiana),  with  one  rose, 
illustrate  this  fact  admirably.  "I  have  had  a 
number  of  sports  of  the  Perle  des  Jardins  rose," 
he  writes  me,  "  in  our  greenhouses.  The  first  one 
was  a  double  silvery  pink  with  a  short  bud,  and  a 
very  double,  somewhat  quartered  flower.  The 
stock  of  this  I  sold,  as  a  new  variety,  for  fifty 
dollars.  The  next  sport  was  a  white  Perle.  [The 
Perle  is  a  golden-yellow  rose.]  I  sold  a  plant  of 
Perle  to  a  local  customer,  who  afterwards  com- 
plained that  it  was  not  true  to  name,  because  the 
flower  was  white.  She  took  it  to  be  Cornelia 
Cook.  I  went  to  see  the  rose,  and  found  a  Perle 
rose  in  everything  but  color.  I  secured  the  plant, 
and  was  intending  to  introduce  it,  when,  within 


170  BORROWED    OPINIONS. 

a  few  months,  I  heard  that  Nanz  &  Neuner,  of 
Louisville,  Kentucky,  had  one,  and  that  a  London 
firm  had  another ;  and  later  I  found  that  one  had 
originated  in  Germany.  Another  sport  of  Perle 
was  a  single  rose,  like  Isabella  Sprunt.  Another 
was  like  a  Madame  Falcot.  At  another  time  a 
whole  branch  sported  into  a  form  with  a  long, 
slender  bud  (about  two  inches  long  and  five- 
eighths  inch  in  diameter),  with  only  two  cal}Tx 
lobes,  and  only  two  petals,  —  which  were  very 
broad, — in  each  cycle  or  series.  This  sport  was 
really  a  monstrosity,  and  I  could  not  propagate 

it.-] 

The  so-called  ornamental  plants  are  not  the 
only  ones  which  present  these  examples  of  hetero- 
morphism.  Fruit  trees  furnish  very  remarkable 
examples.  We  will  cite  some  cases,  beginning 
with  those  furnished  by  the  cherry  called  Anglais 
hatif  [Early  English].  The  most  curious  sport 
given  us  by  this  cherry  is  that  which  we  call 
Cerisier  Anglais  heterophylle  or  a  feuilles  de 
saule  [heterophyllous  or  willow-leaved  English 
cherry].  This  is  the  history  of  the  sport: 
Upon  a  young  tree  whose  parts  are  normal,  we 
see,  sometimes  suddenly  and  without  apparent 
cause,  a  vigorous  bud  develop,  which  bud,  instead 
of  producing  leaves  of  the  ordinary  form,  bears 
those  which  are  very  long  and  narrow,  often 
somewhat    falcate,    and    often    irregularly   erose. 


CARRIERS   ON   CHERRY    SPORTS.  171 

Grafted,  this  variety  presents  very  singular  pecu- 
liarities, as  follows:  so  long  as  it  preserves  its 
exceptional  characters  the  plant  does  not  nourish, 
but  as  it  constantly  tends  to  lose  them  we  observe 
that  when  the  leaves  have  almost  returned  to  the 
normal  form  the  trees  flourish  and  bear.  Never- 
theless, this  variety  never  resumes  identically  the 
characters  of  the  type  from  which  it  came.  Its 
aspect  is  always  distinct.  The  tree  is  never 
fertile,  and  its  fruit  also  differs  from  that  of 
the  Early  English.  The  young  shoots  preserve 
their  accidental  character,  and  each  year  the  leaves 
which  it  develops  are  nearly  identical  to  those 
which  the  variety  produced  when  it  was  first 
developed. 

This  variety  is  not  the  only  one  which  is  pre- 
sented by  the  Early  English.  Thus,  when  the 
trees  are  old,  it  frequently  happens  that  we  find 
on  the  same  individual  three  kinds  of  fruits,  dis- 
tinct in  their  times  of  maturing.  There  is,  first, 
the  Early  English,  whose  fruits  become  black; 
the  Late  English,  whose  fruits,  of  a  beautiful 
deep  red,  shining  as  if  varnished,  ripen  later. 
Finally,  we  nearly  always  find  another  variety, 
very  late,  whose  fruits,  a  little  smaller,  are  still 
entirely  green  when  the  other  two  have  been 
gathered  a  long  time.  In  these  three  sports,  the 
differences  are  shown  only  on  the  fruits.  The 
Indule  cherry  is  also  only  a  sport  from  the  Early 


172  BORROWED    OPINIONS. 

English.  It  is  distinguished  by  its  foliage  and 
earliness.  The  Early  English  cherry  is  not  the 
only  one  which  furnishes  bud- varieties  pertaining 
to  the  fruits.  We  find  analogous  examples  in 
the  May  Duke,  Cherry  Duke,  and  Reine  Hor- 
tense.  These  varieties,  indeed,  have  produced 
on  different  branches  of  the  same  individual  sub- 
varieties  whose  fruits  ripened  a  fortnight  later 
than  normally.  Grafted,  each  of  these  sub- 
varieties  preserves  its  accidental  character. 

A  phenomenon  analogous  to  the  preceding  ones 
is  shown  each  year  at  the  Museum  upon  an  or- 
dinary double-flowered  cherry.  The  tree  upon 
which  this  anomaly  was  developed  is  nearly  four- 
teen inches  in  diameter,  is  grafted  on  the  Sainte- 
Lucie  about  twenty-seven  inches  above  the  ground. 
Above  the  junction  the  stem  is  naked  for  about  six 
and  a  half  feet.  At  this  height  is  a  large  branch, 
which  every  year  is  covered  with  extremely  double 
flowers,  whilst  the  flowers  of  other  branches,  ex- 
panding very  much  later,  are  scarcely  half  double, 
and  yield  fruits. 

The  Coe  violette  plum  is  an  example  of  dichro- 
ism.  It  is  a  bud-variety  which  was  produced  on 
the  White-fruited  Coe,  and  which,  grafted,  is 
maintained  with  all  the  characters  which  it  pre- 
sented at  the  time  of  its  appearing.  We  have 
very  often  observed  upon  the  Damas  de  Tours 
plum  an  instance  almost  the  same  as  the  preced- 


CARRIERE   ON   SPORTS    OF   FRUITS.  173 

iner.  On  the  same  tree  there  were  branches 
which  bore  fruits  different  in  form  and  color,  and 
differing  a  fortnight  in  time  of  maturing.  Thus, 
while  the  fruits  of  the  type  are  very  large,  length- 
ened, of  a  deep  red  color  which  recalls  the  Pond 
Seedling,  marked  only  on  one  side  by  a  very 
slight  furrow,  the  fruits  of  the  later  sub-variety 
are  a  little  smaller,  and  their  form  is  that  of  the 
ordinary  Reine  Claude  ;  they  are  of  an  herba- 
ceous green,  which  passes  more  or  less  into  a  very 
clear  red  ;  the  stem,  arched,  swollen  at  the  base, 
is  inserted  in  a  cavity  quite  large  by  the  widening 
of  the  furrow,  whilst  the  stem  of  the  typical  fruits 
is  erect,  little  or  not  at  all  swollen,  inserted  in  a 
very  small  cavity  placed  almost  on  the  surface  of 
the  fruit. 

Another  plum,  the  Prunier  Puget,  presents  the 
following  peculiarities :  Upon  the  same  branch  it 
very  frequently  happens  that  there  are  fruits  of 
a  violet-red,  dotted  or  striped  with  red-green. 
We  find  some,  also,  which  present  all  the  inter- 
mediate tints  and  others  which  are  almost  uni- 
colored.  By  multiplying  them  separately,  there 
may  be  a  chance  to  establish  these  varieties  and 
to  obtain  several  from  one  tree. 

We  have  seen  on  a  red-fruited  currant  bush  a 
branch  which  bore  fruits  as  white  as  those  of  the 
Hollande  a  fruits  blancs  [White  Dutch]. 

The  fact  of  the  nectarine  coining  suddenly  from 


174  BORROWED    OPINIONS. 

a  peach  can  no  longer  be  doubted.  Recent  ex- 
amples have  come  to  support  the  experiments  of 
certain  authors,  notably  Sieulle. 

Two  other  similar  examples,  of  which  we  ought 
to  speak,  are  furnished  by  two  varieties  of  Chasse- 
las  grapes,  one  known  as  Chasselas  panache  [Va- 
riegated Chasselas]  and  Chasselas  Suisse  [Swiss 
Chasselas] .  Both  appear  to  have  come  from  a  va- 
riety with  black  fruits,  the  color  which  predomi- 
nates in  them.  These  are  the  peculiarities  which 
they  present :  almost  all  the  bunches  bear  some 
fruits  more  or  less  variegated  or  striped,  white 
in  Chasselas  Suisse,  red  in  Chasselas  panache. 
But  it  happens  frequently  that  the  elements  are 
separated  and  that  we  have  then,  upon  different 
shoots,  sometimes  upon  the  same  shoot,  bunches 
of  grapes  of  different  color,  almost  entirely  white 
if  they  belong  to  the  Chasselas  Suisse,  and  red  if 
they  belong  to  the  Chasselas  panache.  One  of 
the  varieties  is  only  a  modification  of  the  other, 
which  is  itself  only  a  modification  of  some  other. 

The  pear  Saint-Germain  gris,  whose  deep  gray 
fruits  are  very  different  in  appearance  from  those 
of  the  ordinary  Saint-Germain,  is  a  bud-variety 
which  was  produced  upon  a  branch  of  the  latter, 
and  which,  multiplied  by  grafting,  is  maintained 
in  all  its  characters.  A  similar  variety  was  pro- 
duced on  the  Messire-Jean,  so  that  at  present  we 
possess  in  the  gardens  a   Messire-Jean  gris,  and 


CARRIERS   ON   SPORTS   OF   FRUITS.  175 

a  Messire-Jean  jaune  [gray  and  yellow  Messire- 
Jean].  To  these  examples  we  will  add  two  other 
analogous  ones,  which  were  recorded  in  the  Bul- 
letin de  VAcademie  des  Sciences,  xxxiv.,  meeting 
of  May  17th.  One,  given  by  M.  Dureau  de  la 
Malle,  refers  to  the  Bon  Chretien  pear,  which 
produced  sometimes  typical  fruits  and  at  others 
"  of  a  form  entirely  different  and  unknown."  The 
other  example,  cited  by  M.  Mourriere,  professor 
at  Bernay,  has  reference  to  an  apple  which,  on  the 
same  branches,  produced  fruits  which  had  the 
appearance  of  a  Reinette  rousse  and  others  which 
resembled  a  kind  of  Reinette  du  Canada.  The 
latter  is  smooth,  punctated,  and  often  of  a  bright 
red  upon  one  side.  [The  recent  experiments 
of  Waite,  in  this  country,  respecting  the  imme- 
diate influence  of  pollen,  raise  the  question  if 
some  of  these  minor  variations  in  form  of  the 
pear  fruit  may  not  have  arisen  from  vagaries  of 
pollination.] 

The  various  examples  which  we  have  cited  are 
common  to  a  very  large  number  of  plants,  among 
which  we  will  cite  the  banana  and  sugar-cane. 
Indeed,  although  these  plants  do  not  produce 
seeds,  we  find  in  each  species  a  large  number  of 
varieties  which  are  very  distinct  in  vigor,  aspect, 
habit,  and  in  the  banana  in  form,  size,  and  quality 
of  fruit.  All  these  varieties  are  produced  by 
bud-variation.     These  remarks  can  be  applied  to 


176  BORROWED    OPINIONS. 

other  monocotyleclonous  plants,  as  Arundo,  Pha- 
laris,  Bamboos,  Dracaena,  Yucca,  etc. 

[Carriere  cites  the  different  shapes  and  colors 
of  beans  in  the  same  pod  as  examples  of  bud- 
variation,  but  it  is  a  question  if  these  differences 
are  not  determined  in  the  seed  of  the  previous 
year.  At  all  events,  since  there  is  only  a  single 
year  in  the  life  of  the  bean,  we  prefer  to  ascribe 
variations  in  it  to  the  generation  of  the  parents 
from  which  it  has  just  sprung.  There  is  no  pre- 
vious year's  growth  of  the  same  individual  with 
which  to  compare  variations  and  to  ascertain  if 
they  are  bud-departures  from  the  type.    Page  118.] 

2.    List  of  Bud-varieties.1 

After  having  sought  to  present  certain  examples 
of  bud-variation  which,  by  their  importance,  seem 
to  be  sufficient  to  fix  the  attention,  we  will  con- 
tinue by  the  enumeration  of  a  certain  number  of 
others,  without,  however,  entering  into  details  for 
each  one  of  them.  Sometimes  we  shall  give  only 
the  name  of  the  variety.  If,  however,  they  pre- 
sent particular  interest,  either  in  a  practical  or 
scientific  point  of  view,  we  shall  dwell  upon  them 
more  at  length,  considering  either  their  origins  or 
peculiarities.      [The  garden  names  of  the  plants 

1  The  student  should  also  consult  Darwin's  "Animals  and 
Plants  under  Domestication," 


carriere's  list  of  bud-varieties.     177 

are  given  essentially  as  they  stand  in  the  original, 
for,  as  the  purpose  of  this  list  is  to  acquaint  hor- 
ticulturists with  the  nature  and  frequency  of  bud- 
variations,  1  have  considered  it  unnecessaiy  to 
make  any  particular  attempt  to  revise  the  nomen- 
clature. The  names  are  familiar,  and,  therefore, 
useful  as  they  stand.] 

It  would  have  been  easy  to  extend  this  enumera- 
tion of  examples  of  bud- variation.  We  have  not 
thought  it  necessary  because,  aside  from  leading 
us  too  far,  the  real  interest  of  the  subject  would 
gain  nothing  by  it.  We  have,  then,  thought  it 
our  duty  to  put  limits  upon  a  subject  which  has 
no  limits. 

Acer  eriocarpum,  fasciatum. 

Very  remarkable  for  its  much  fasciated  branches. 
This  variety  showed  itself  at  the  Museum  in  1857 
upon  a  seedling  Avhich,  during  the  first  two  years, 
presented  nothing  abnormal.  In  the  third  year, 
when  the  tree  had  been  cut  back,  the  sport 
appeared,  since  which  time  it  has  maintained  itself 
Avith  all  its  characters.  This  variety  is  to  A. 
eriocarpum  what  the  variety  montrosa  is  to  Sam- 
bucus  nigra. 

Acorus  gramineus,  variegata.1 

1  When  a  name  is  not  followed  by  remarks,  the  reader  is  to 
understand  that  it  represents  a  known  variety  and  that  the 
name  of  the  species  indicates  the  origin  of  the  variety.  —  L.  H.  B. 


178  BORROWED   OPINIONS. 

iEsculus  rubicuncla,  variegata. 

[iEsculus  Hippocastanum,  double  -  flowered. 
Upon  a  well-known  Horse  Chestnut  tree  in  the 
environs  of  Geneva  the  owner,  in  1822  or  1823, 
detected  a  single  branch  bearing  double  flowers. 
This  still  continues  to  bear  double  flowers  and 
grafts  from  it  do  the  same.  It  is  thought  to  be 
the  original  of  all  the  doubled-flowered  Horse 
Chestnuts  in  the  world.  — A.  De  Candolle  in  Acad. 
Sei.,  Paris,  1875,  quoted  by  Asa  Gray,  Sillimans 
Journ.  3dser.  x.  238]. 

Agathsea  amelloides,  variegata. 
Ageratum  Mexicanum,  nanum. 

This  plant,  which  is  now  used  to  so  much  ad- 
vantage for  borders,  is  the  product  of  a  branch 
which  developed  accidentally  from  A.  Mexicanum. 
Its  heads  are  almost  sessile  and  a  little  irregular, 
borne  so  close  to  the  leaves  as  to  make  the  plant 
undesirable  from  some  points  of  view.  The  type 
plants,  on  the  contrary,  which  are  very  much 
larger,  have  the  heads  large  and  regular  and  raised 
on  long  peduncles. 

Ageratum  Mexicanum,  intermedium. 

This  variety,  which  is  a  bud-variety  of  sec- 
ond degree,  that  is,  a  sport  from  a  sport  (from 
the  variety  nanum),  is  intermediate.  The  plants 
are  very  floriferous.     Their  heads  are  also  better 


carriere's  list  of  bud- varieties.      179 

than  those  of  the  type,  and  as  they  are  borne 
upon  longer  peduncles,  the  plants  are  not  only 
suitable  for  garden  ornament  but  for  cut  flowers. 
The  dimensions  of  this  variety  are  intermediate 
between  the  last  variety  and  the  specific  type. 

Ageratum  Mexicamim,  variegatum. 

This  differs  little  from  the  type  except  by  its 
leaves  being  variegated  with,  yellowish-white  on 
the  margins.  Its  inflorescence  is,  however,  a  little 
more  slender  and  its  heads  are  smaller.  In  gen- 
eral, the  plant  is  "  leggy,"  weak. 

Almond  with  variegated  leaves. 

Leaves  bordered  and  made  satin-like  with  white ; 
vegetation  delicate.  It  sometimes  returns  to  the 
type. 

Anemone  Japonica,  Honorine  Jobert. 

Very  vigorous  and  very  beautiful.  This  vari- 
ety, of  which  the  flower  is  white,  is  a  bud-variety 
from  the  so-called  A.  hybrida  or  A.  elegans, 
which  was  obtained  in  England  by  M.  Gordon  by 
crossing  A.  Japonica  with  A.  vitifolia.  The  va- 
riety was  produced  some  years  ago  at  M.  Jobert 's, 
amateur  at  Verdun. 

Apricot  with  variegated  leaves. 


180  BORROWED    OPINIONS. 

Aralia  trifoliata,  Cookii. 

This  plant  has  its  leaves,  in  general,  simple, 
long,  and  narrow. 

Arunclo  Donax,  variegata  argentea,  and  A.  Donax, 

variegata  aurea. 

These  varieties  differ  from  the  type  by  the 
leaves  being  bordered  with  white  in  the  first, 
and  with  yellow  in  the  second.  They  are  much 
more  delicate  than  the  type. 

Aspidistra  elatior,  variegata. 

Aster  bicolor. 

This  plant,  which  we  believe  not  to  be  a  dis- 
tinct species  but  simply  a  dwarf  form,  very  prob- 
ably a  bud-variety  of  A.  versicolor,  produced  at 
the  Museum  in  1856,  upon  one  of  its  stems,  a 
vigorous  bud  which  presents  all  the  characters  of 
A.  versicolor  except  that  it  is  a  little  smaller. 
This  variety,  to  which  we  have  given  the  vari- 
etal name  Major,  has  preserved  all  its  characters 
Avhen  multiplied  by  root-cuttings,  and  to-day  is 
still  one  of  the  most  beautiful  perennial  plants. 

Azalea  Indica,  Dieudonne  Spae. 

Flowers  salmon,  margined  with  white.  It  is 
a  sport  from  A.  formosa,  Ivery,  which  has  rose 
flowers. 


carriere's  list  of  bud-varieties.     181 

Azalea  Indica,  Beaute  de  l'Europe. 

This  variety  has  flowers  white  at  the  base, 
variegated  with  red.  It  is  a  sport  from  A.  deli- 
cata,  which  has  deep  salmon  flowers. 

Azalea  Indica,  Criterion. 

Flowers  deep  rose  bordered  with  white.  This 
is  a  sport  from  A.  Iveriana,  which  has  flowers 
white,  striped  with  rose. 

Azalea  Indica,  alba  rosea. 

Flowers  rose,  slightly  bordered  with  white.  A 
bnd- variety  from  A.  Iveriana. 

Azalea  Indica,  exquisita  grandiflora. 

Flowers  deep  rose  bordered  with  white.  It  is 
a  bnd- variety  from  A.  alba  perfecta,  which  has 
flowers  white,  very  lightly  striped  with  rose. 

Buxns  Balearica,  cncnllata. 

This  bud- variety  of  B.  Balearica  differs  from 
its  parent  by  its  smaller  leaves,  which  are  very 
strongly  convex,  and  rounded  in  the  middle. 

Buxus  sempervirens,  argentea. 
Buxus  sempervirens,  aurea. 
Buxus  sempervirens,  marginata. 

All  these  varieties  are  distinguished  from  the 
type  by  their  leaves  being  variegated  or  bordered 
with  either  white  or  yellow. 


182  BORROWED    OPINIONS. 

Camellia  Japonica,  Comte  de  Paris. 

This  variety,  which  has  strongly  striped  rose- 
flesh-colored  flowers,  is  a  sport  from  the  Duchesse 
d'Orleans,  which  bears  white  striped  flowers.  This 
variety  is  not  only  much  more  vigorous  than  its 
parent,  but  it  has  the  merit  of  fully  expanding  its 
flowers,  while  the  buds  of  the  Duchesse  d' Orleans 
almost  always  fall  before  opening. 

Camellia  Japonica,  Montironi  rosea. 

This  plant,  whose  flowers  are  entirely  rose,  is 
a  sport  from  the  Montironi,  which  has  white,  very 
lightly  striped  flowers. 

Camellia  Japonica,  Giardino  Franchetti. 

Flowers  deep  rose,  bordered  with  white.  It  is 
an  offshoot  from  C.  Targioni,  which  has  white 
flowers  lightly  striped  with  rose. 

Camellia  Japonica,  Comtesse  Woronzoff. 

This  variet}^,  which  has  delicate  rose  flowers,  is 
a  sport  from  C.  centifolia  alba,  whose  flowers 
are  pure  white. 

Camellia  Japonica,  Giardino  Schmitz. 

Flowers  delicate  rose-color.  It  is  a  bud-variety 
from  the  Elisa  Centurion,  which  bears  very  lightly 
rose-striped  white  flowers. 


carrieke\s  list  of  bud-varieties.     183 

Camellia  Japonica,  Imperatrice  Eugenie. 

Flowers  rose-flesh-colored.  A  bud-variety  from 
Montironi,  whose  flowers  are  very  striped  with 
rose. 

Camellia  Japonica,  Paolina  Armari. 

Flowers  deep  rose.  Bud-variety  from  INIiss 
Abby  Wilder,  which  has  white,  lightly  rose-striped 
flowers. 

Camellia  Japonica,  Princesse  Aldrovandi. 

Flowers  rose,  bordered  with  white.  Sport  from 
Teutonia,  which  bears  flowers  white,  rose-striped. 

Camellia  Japonica,  Bicolor  de  la  Reine. 

Flowers  rose,  bordered  with  white.  It  is  a 
sport  from  de  la  Reine,  whose  flowers  are  white, 
lightly  striped  with  rose. 

Last  year  we  saw  upon  a  camellia  with  rose 
flowers,  some  branches  bearing  flowers  completely 
white. 

Cephalotaxus  pedunculata,  fastigiata. 

This  variety,  which  has  been  described  and 
figured  as  being  a  species  of  Podocarpus  (P. 
Koraiana),  is  an  example  of  bud-variation.  We 
had  proof  of  this  statement  at  the  Museum  in 
1863.  Having  made  cuttings  from  a  certain  num- 
ber of  branches  of  the  so-called  Podocarpus,  one 


184  BORROWED    OPINIONS. 

of  them,  instead  of  producing  simple  and  scat- 
tered, strictly  erect  brandies  bearing  scattered 
leaves,  produced  wliorled,  horizontal  branches 
bearing  distichous  leaves.  The  variety  fastigiata 
is  to  C.  pedunculata  what  Taxus  baccata,  fastigi- 
ata, is  to  T.  baccata. 

Cereus  Peruvianus,  monstrosus. 
Sometimes  returns  to  the  type. 

Clematis  bicolor  or  Sieboldii. 

This  plant,  of  which  the  flowers,  violet  inside, 
are  almost  double  from  the  transformations  of  the 
stamens,  is  a  sport  from  C.  florida,  which  has 
single  greenish- white  flowers.  We  have  several 
times  had  occasion  to  ascertain  that  such  is  the 
origin  of  this  clematis. 

The  variety  known  as  C.  bicolor,  flore  pleno, 
which  we  sometimes  call  Atragene  Americana, 
so  remarkable  for  its  enormous  greenish-white 
flowers,  is  a  direct  sport  from  C.  bicolor,  conse- 
quently a  bud- variety  of  the  second  degree  from 
C.  florida,  a  fact  which  Ave  have  been  able  to 
verify  again  this  year.  On  a  plant  of  C.  bicolor, 
planted  in  the  open  air,  there  is  developed,  almost 
from  the  base,  a  branch  which  bore  flowers  en- 
tirely full,  monstrous,  yellowish-green,  so  that  the 
two  bud- varieties  —  C.  bicolor  and  its  variety  flore 
pleno  —  were  united  upon  the  same  individual. 


caeiiiere's  list  op  bud-varieties.     185 

Clematis,  Helena  monstrosa. 

This  plant  is  none  other  than  C.  Helena  which, 
by  bud- variation,  is  transformed  and  has  become 
double  flowered.  This  example  is  analogous  to 
that  which  is  produced  by  C.  bicolor. 

Cheiranthus  Cheiri,  variegata  flore  pleno. 

Sport  from  the  double-flowered  yellow  gilly- 
flower of  the  walls. 

Cherry.     See  page  170. 

Cornus  sanguinea,  variegata. 

Cornus  Mas,  variegata. 

Cytisus  Adami. 

Whatever  may  be  the  origin  of  this  plant, 
whether  a  hybrid,  as  is  generally  believed,  or  a 
peculiar  form,  we  propose  here  to  say  nothing 
concerning  it  beyond  a  verification  of  its  peculiar- 
ities. It  develops  very  frequently  and  normally, 
so  to  speak,  some  branches  of  C.  Laburnum 
and  others  belonging  to  C.  purpureus.  When 
we  graft  separately  these  two  kinds  of  branches, 
these  species  remain  invariable,  although  the 
grafts  were  taken  from  C.  Adami. 

Dactylis  glomerata,  variegata. 


186  BORROWED   OPINIONS. 

Echinocactus  multiplex,  cristata. 

This  variety,  instead  of  having  a  regular, 
lengthened,  melon-like  stem,  forms  a  thick  mass 
which  extends  itself  into  little  fan -shaped 
bunches,  and  instead  of  longitudinal  furrows, 
large  and  deep,  and  separated  by  protuberances 
upon  which  are  borne  long,  very  rigid  spines 
(about  three  -  fourths  to  one  and  two -fifths 
inches) ;  the  variety  has  only  very  slight  fur- 
rows or  kind  of  folds  disposed  transversely  to 
the  direction  of  the  fasciation,  consequently  in 
a  contrary  direction  to  those  which  are  presented 
by  the  type,  and  upon  the  borders  are  spurs 
(about  two-fifths  inch  long)  disposed  in  stars. 
In  a  word,  the  variety  is  entirely  different  from 
its  parent. 

Elseagnus  reflexa,  variegata  argentea  and  varie- 
gata  aurea. 

These  two  varieties  differ  from  the  type  in 
having  their  leaves  bordered,  respectively,  with 
white  or  yellow. 

Elseagnus  pungens,  variegata. 

Euonymus  Japonica,  argentea  and  aurea. 

These,  especially  aurea,  return  sometimes  to  the 
type. 


caerieke's  list  of  bud-varieties.     187 

Euonymus  Japonica,  flavida. 

This  plant,  which  developed  upon  a  type  plant 
with  green  leaves  in  1862,  is  distinguished  by  its 
leaves  being  bordered  with  yellowish-green,  some- 
times with  nearly  white.     It  is  vigorous. 

Euonymus  Japonica,  fasciata. 

Very  remarkable  for  its  much  fasciated  branches. 
This  variety  appeared  at  the  Museum  in  1864,  upon 
a  typical  E.  Japonica. 

Euonymus  Japonica,  calamistrata. 

This  sprung  from  the  variety  argentea,  from 
which  it  differs  in  its  more  slender  parts.  Its 
leaves  are  smaller  and  crisped  as  if  erose. 

E.  Japonica  has  also  produced  many  other  bud- 
varieties,  which  differ  in  variegation,  or  sometimes 
even  by  the  form  of  the  leaves.  It  is  more  than 
probable  that  the  various  varieties  which  have  been 
introduced  recently  from  Japan  are  bud- varieties. 

Fagus  sylvatica,  fern-leaved. 

This  variety  once  presented  the  following 
peculiarity  :  Having  grafted  it  upon  the  com- 
mon beech,  the  branches  developed  from  each 
side  of  the  stem  almost  distichously.  All  those 
upon  one  side  bore  leaves  similar  to  those  of  the 
common  beech,  whilst  those  upon  the  other  side 
bore  only  laciniated  leaves. 


188  BORROWED    OPINIONS. 

Ficus  scandens,  microphylla. 

This  variety,  which  we  sometimes  meet  in  com- 
merce under  the  name  of  F.  buxifolia,  is  a  bud- 
variety  which  appeared  in  1856  at  the  Botanic 
Garden  of  Orleans  upon  a  plant  of  F,  scandens 
grown  in  a  greenhouse.  Its  leaves  are  very  small, 
someAvhat  suborbicular  and  marked  with  brown. 
This  variety  is  preserved  in  all  its  characters, 
both  upon  the  original  plant  and  in  all  the  multi- 
plications which  have  been  made  of  it. 

Fontanesia  phyllireoides,  variegata. 

This  very  pretty  variety  appeared  at  the 
Museum  in  1854.  Since  its  appearing,  this  vari- 
ety has  not  varied.  Its  branches,  of  a  yellowish- 
green,  are  slender,  and  the  leaves  are  deeply 
bordered  with  yellowish- white. 

Fraxinus  Americana,  variegata. 

Fraxinus  excelsior,  jaspidea. 

This  variety  is  distinguished  by  its  bark  being 
striped  or  slightly  ribboned  with  yellow. 

Fraxinus  excelsior,  variegata. 

The  common  ash  has  produced  several  sports 
Avhich  are  marked  by  the  variegation  of  their 
leaves.  This  one  has  yellow  and  white  disposecV 
in  bands  and  bordering  the  leaves,  or  sometimes 


caiirieke's  list  of  bud- varieties.     189 

in  spots  upon  all  parts  of  the  blade,  as  upon  the 
leaves  of  Aucuba,  for  example  ;  hence  the  various 
names,  argentea,  aurea,  striata,  maculata,  aucubaj- 
folia,  etc. 

Gardenia  radicans,  variegata. 

In  this  instance  the  variation  is  two-fold.  The 
leaves  are  bordered,  and  are  also  much  narrower 
than  in  the  type. 

Gillyflower,    called    Savoyarde,    with    variegated 

leaves. 

This  is  a  sport  from  the  double-flowered  brown 
gillyflower. 

Grape.     See  Vine. 

Hedera.     Variegated  tree-ivy. 

This  sub- variety  is  a  bud- variety  from  the  so- 
called  tree-ivy  (lierre  en  arbre,)  from  which  it 
varies  only  in  the  yellowish-white  variegations  of 
the  leaves. 

What  we  call  tree-ivy  is  a  common  ivy,  or  one 
of  its  varieties,  arrived  at  the  full-grown  state  and 
which  then  fruits.  The  branches  are  large,  short, 
cylindrical,  and  destitute  of  climbing  roots.  The 
leaves,  instead  of  being  lobed,  are  heart-shaped, 
more  or  less  lengthened,  sometimes  very  obtusely 
rounded.  As  there  are  several  forms  of  creeping 
ivy,  so  there  are  several  sub-varieties  of  the  tree- 


190  BORROWED    OPINIONS. 

ivy.  They  partake  of  the  character  of  the  varieties 
from  which  they  come  and  are  distinguished  by  the 
form  and  dimensions  of  the  leaves,  by  the  size  of 
the  branches,  these  characters  all  depending  upon 
the  vigor  and  appearance  of  the  mother  varieties. 
We  obtain  the  tree-ivy  either  by  cuttings  or  by 
grafting  from  adult  branches,  that  is,  branches 
which  have  been  modified  by  fructification.  They 
then  branch  and  form  very  pretty  bushes.  Some- 
times, especially  near  the  ground  or  in  badly  aired 
places,  branches  arise  supplied  with  climbing  roots, 
bearing  leaves  more  or  less  lobed,  and  which  creep 
and  take  root  as  soon  as  they  touch  the  ground. 
Here,  in  the  case  of  the  tree-ivy,  is  an  instance  of 
bud-variation  due  to  the  maturity  of  the  individual. 

Hibiscus  Syriacus,  flore  pleno  variegata. 

This  variety,  whose  leaves  are  variegated  with 
yellowish-white,  appeared  in  1858  upon  a  plant 
with  entirely  green  leaveSc 

Hibiscus  Syriacus,  variegata. 

Remarkable  in  the  variegation  of  its  leaves.  Its 
flowers  are  similar  to  those  of  the  last.  It  is  a  va- 
riation directly  from  the  type.    It  is  not  vigorous. 

Hyacinth. 

The  double  blue  or  Globe  terrestre  is  a  bud- 
variety  from  the  double  white  or  Sultan  Achmet. 


CARRIERE'S   LIST   OF   BUD-VAKI  E  TIES.       191 

The  double  white  with  blue  eye,  or  Sphaera  Muudi, 
is  a  sport  from  the  double  white.  The  single  red, 
called  Acteur,  cultivated  for  a  very  long  time 
without  varying,  has  produced  by  bud-variation 
at  Hemstede,  near  Haarlem,  a  variety  with  double, 
imbricated  red  flowers.  The  hyacinth  Ami  du 
Cceur,  with  single  blue  flowers,  also  long  culti- 
vated without  varying,  lias  produced,  from  the 
same  bulb,  two  flower  stalks,  one  of  which  bore 
flowers  dregs-of-wine  color,  while  the  other  bore 
flowers  of  a  delicate  flesh-colored  rose. 

Hydrangea  Hortensia. 

This  sterile  plant  is  a  sport  from  the  form  called 
H.  Japonica,  analogous  to  those  which  are  pro- 
duced upon  Viburnum  Keteleerii  and  V.  Opulns. 

H}Tdrangea  Japonica,  variegata. 

Differs  from  the  type  only  by  its  leaves  being 
bordered  with  white. 

Ilex  Aquifolium,  calamistrata  variegata. 

This  variety  is  a  sport  from  the  I.  calamis- 
trata, which  is  a  sport  from  the  common  holly. 

Ilex  Aquifolium,  ferox  aurea,  and  ferox  argentea. 
Bud-varieties    from    the    variety    ferox,    from 
which  they  differ  in  the  variegation  of  the  leaves, 
yellow  in  the  first,  white  in  the  second. 


192  BORROWED   OPINIONS. 

The  very  numerous  varieties  of  common  holly 
in  cultivation  are  for  the  most  part  fixed  bud- 
varieties. 

Iris  spectabilis. 

This  plant,  so  remarkable  for  its  color,  is  a  bud- 
variety  from  Iris  Xiphium,  from  which,  however, 
it  is  very  different. 

Juniperus  communis,  variegata. 

Juniperus  excelsa,  variegata. 

Juniperus  Virginiana,  variegata. 

Juniperus  Virginiana,  monstrosa. 

This  variety,  which  arises  from  knaurs  or  burrs, 
is  shown  frequently  upon  the  Virginian  juniper 
(red  cedar). 

Lamium  album,  variegatum. 

Laurocerasus  vulgaris,  angustifolia. 

This  plant,  which  for  a  long  time  has  gone  under 
the  name  of  Hartogia  Caj)ensis,  is  a  bud-variety,  a 
fact  which  we  have  been  able  to  ascertain  several 
times.  Its  leaves  are  very  straight,  long,  of  a 
clear  green,  and  more  strongly  toothed  than  those 
of  the  plant  from  which  it  comes.  It  is  very  con- 
stant.    We  have  a  record  of  its  variation. 


carriere's  list  of  bud-varieties.     193 

Laurocerasus  vulgaris,  variegata, 
Laurocerasus  Lusitanica,  variegata. 

Ligustrum  Japonicum,  variegatum. 

The  L.  Japonicum  appears  to  be  subject  to  bud- 
variations,  especially  in  the  direction  of  dichroism. 
We  have  already  produced  from  it  several  varie- 
ties distinct  in  the  color  or  disposition  of  the 
variegations,  the  varieties  receiving  names  accord- 
ing to  their  character.  There  is  one  which  differs 
somewhat  in  the  form  of  its  leaves. 

Ligustrum  ovalifolium,  aureum. 

This  variety,  which  is  distinguished  by  having 
its  leaves  bordered  or  ribboned  with  yellow,  was 
produced  at  the  Museum  in  1861.  It  comes  from 
a  branch  which  was  developed  spontaneously  upon 
a  type  plant.     It  is  unstable. 

Ligustrum  vulgare,  variegatum. 

This  variety  has  leaves  variegated  with  yellow. 
It  occurs  quite  frequently  in  the  wild  state.  We 
have  found  it  several  times  in  the  woods.  It  is 
not  stable. 

Lilac,  common,  variegated. 

Lilac,  Persian,  laciniate-leaved  and  white-flowered. 

Although  we  are  not  able  to  state  precisely  when 

these  two  sports  appeared,  we  have  no  doubt  that 


194  BORROWED    OPINIONS. 

they  are  bud-varieties,  as  the  Persian  lilac  never 
gives  seeds.  The  origin  of  the  Persian  lilac  itself, 
even,  is  in  much  doubt. 

Mamillaria  nivea,  dedalea. 

This  variety  forms  a  compact  mass  whose  folds 
and  circumvolutions  are  disposed  in  a  sort  of  laby- 
rinth (whence  dedaleci),  giving  it  a  little  the  ap- 
pearance of  calves'  pluck.  The  type  from  which 
this  variety  comes  forms  a  melon-formed  cylinder 
which  is  slightly  swollen  at  the  summit.  It  bears 
spines  disposed  in  bundles  and  from  about  four- 
fifths  inch  to  one  inch  and  a  fifth  in  length,  rigid, 
very  sharp,  surrounded  at  the  base  by  a  series  of 
smaller  ones  disposed  in  the  form  of  a  star.  The 
variety,  on  the  other  hand,  aside  from  its  peculiar 
form,  has  no  spines.  It  is  invested  upon  all  its 
parts  with  silky  hairs,  silvery  and  as  soft  as  felt 
to  the  touch.  The  parent  and  offspring  have 
nothing  in  common  in  their  general  form. 

Mentha  rotundifolia,  variegata. 

Molinia  coerulea.  variegata. 

Musa  paradisiaca,  vittata. 

This  is  distinguished  from  the  type  by  the  white 
bands  upon  its  leaves.  The  variegation  is  con- 
spicuous upon  the  yellow  plants.  It  often  disap- 
pears with  time,  so  that  in  the  old  plants  we  do 
not  often  find  any  trace  of  it. 


caiumeue\s  list  of  bud- varieties.     195 

Myrtle,  common,  variegated-leaved. 
Frequently  returns  to  the  type. 

Opuntia  cylindrica,  cristata. 

In  exterior  characters  this  plant  has  nothing  in 
common  with  the  type,  which  forms  a  regular, 
cylindrical  column.  The  variety,  on  the  contrary, 
is  made  up  of  enlarged  pieces  placed  against  each 
other  in  different  ways,  much  the  same  as  those 
presented  by  the  various  species  of  opuntia  which 
we  call  "Semelles  du  Pape." 

Orange  tree,  Turkish. 

This  variety,  which  is  a  sport  from  a  kind  of 
Seville  orange  (probably  from  the  Horned  Seville 
orange),  bears  at  times  upon  its  various  branches 
leaves  narrow  and  irregular  (as  erose),  variegated 
or  rather  satin-bordered,  white,  and,  upon  other 
branches,  green  leaves,  large  and  strongly  eared, 
as  well  as  fruits  which  recall  those  of  the  Horned 
Seville  orange. 

Orontium  Japonicum,  variegatum. 

Osmanthus  Fortunei,1  ovata. 

This  variety  is  unstable.  After  having  pre- 
served it  for  more  than  a  year  without  varying,  it 
has  resumed  in  large  part  its  primitive  character, 
which  is  to  have  leaves  long,  exceedingly  thorny 

1  The  Olea  ilicifolia  of  commerce.  —  Carriere. 


196  BORROWED   OPINIONS. 

and  strongly  nerved.    Sometimes  we  find  branches 
bearing  leaves  of  different  forms. 

Osmanthns  Aquifolius,  variegatus. 

Differs  from  the  type  by  the  yellowish- white 
variegations  of  the  leaves. 

O.  Aquifolius,  which  we  can  consider  as  the 
representative  in  Japan  of  our  common  holly, 
appears,  like  the  holly,  to  be  very  subject  to  bud- 
variation.  We  have  no  doubt  that  the  varieties 
recently  introduced  from  Japan  originated  in  this 
manner. 

Peach,  carnation-flowered  (Persica  dianthiflora), 

and  many-colored  (P.  versicolor). 

These  two  varieties  are  sportive  forms  of  P. 
rosseflora,  of  which  the  flowers  are  very  deep 
red.  Like  this,  the  two  varieties  have  double 
flowers,  but  of  very  different  colors  from  those  of 
their  parent.  The  carnation-flowered  has  flowers 
of  a  flesh-colored  rose.  The  many-colored,  on 
the  contrary,  has  white  flowers  striped  or  rib- 
boned with  brilliant  rose.  This  last  is  very  much 
more  delicate  than  P.  rosseflora  or  the  carnation- 
flowered. 

Peach,  willow-leaved  red  Madeleine. 

This  variety,  remarkable  for  the  form  of  its 
leaves,  which  are   very  long   and  narrow,  plane, 


carriebb's  list  of  bud-vaiuettes.     197 

glossy,  very  shortly  toothed,  is  the  result  of  a 
bud-variation  from  the  variety  designated  by  cer- 
tain horticulturists  as  Madeleine  de  Courson  (red 
Madeleine).  It  appears  to  us  to  have  great  re- 
semblance to  that  very  anciently  known  as  the 
willow-leaved. 

Peach,  laciniate-leaved  red  Madeleine. 

Leaves  very  strongly  and  coarsely  toothed  or 
laciniated. 

Pears,  variegated  fruited. 

The  following  pears  have  given  by  bud- varia- 
tion variegated  varieties  :  Duchesse  d'Angouleme, 
Amanlis,  Guenette  or  Madeleine,  Saint-Germain, 
Bergamotte  d'automne,  Culotte  de  Suisse,  etc. 
These  bud-varieties  are  further  remarkable  in  that 
the  variegations  extend  to  the  branches  and  fruit, 
but  not  to  the  leaves,  a  character  which  distin- 
guishes them  from  the  next  variety,  which  is  like- 
wise a  bud- variety. 

Pear,  Amanlis,  with  }Tellow  bark  and  leaves. 

A  very  remarkable  variety.  We  could  almost 
say  that  it  is  pretty.  It  was  developed  upon  a  stem 
of  Amanlis  which  presented  nothing  abnormal. 
It  is  very  vigorous,  and  produces  a  most  singular 
effect,  with  its  parts  all  yellow  except  the  bark, 
which  is  grayish-white.      It  has  not  yet  fruited. 


198  BORROWED    OPINIONS. 

[One  of  the  most  marked  cases  of  bud- variation 
which  ever  came  under  my  notice  was  observed 
a  few  years  ago  upon  a  tree  of  Onondaga  pear. 
One  branch,  so  placed  as  to  remove  all  possibility 
of  its  being  a  root-sprout  or  a  graft,  bore  about  a 
dozen  pears  which  were  intensely  and  uniformly 
russeted.  They  were  so  different  in  appearance 
from  the  pears  upon  the  remainder  of  the  tree  that 
no  one  would  suppose  for  a  moment  that  they  were 
the  same  variety.  Even  the  Sheldon  does  not 
differ  more  widely  from  the  Onondaga  in  appear- 
ance than  did  this  singular  sport.] 

See  page  174  for  further  notes  on  the  pear. 

Pelargonium  zonale,  Manglesii. 

Distinguished  from  the  species  by  its  white 
variegated  leaves,  which  are  more  deeply  lobed, 
and  by  the  weaker  branches.  It  has,  in  its  turn, 
produced  several  varieties  by  bud- variation. 

The  bud-varieties  produced  by  P.  zonale  and  P. 
inquinans  (which  are  in  reality  only  one)  are  very 
numerous.  There  are  among  them  some  varieties 
of  such  pronounced  characters  that,  if  we  ignored 
their  origin,  we  might  consider  them  species. 

Pelargonium  hederaefolium,  variegatum. 

Phalaris  arundinacea,  picta  and  aurea. 

These  two  varieties  differ  from  the  species  in 
the  variegation,  which  is  produced  by  white    in 


cabbiere's  list  of  bud- varieties.     199 

the  first  case  and  yellow  in  the  second.  They 
are  exactly  representative  of  the  phenomenon 
which  is  observed  in  Arundo  Donax,  as  well  as 
in  the  sugar-cane. 

Phlox  decnssata,  white  Croix  de  Saint-Louis. 

This  variety,  of  which  the  flowers  are  entirely 
white,  appeared  upon  the  variety  Croix  de  Saint- 
Louis  in  1863.  The  parent  variety  has  white- 
striped  rose  flowers,  and  cross-form,  whence  its 
name. 

Phragmites  vulgaris,  variegata. 

Leaves  bordered  or  margined  with  white. 

Picea  excelsa,  tabulaaformis. 

This  variety,  which  attains  a  height  of  scarcely 
more  than  a  foot  or  two,  and  which  spreads  out 
horizontally  so  as  to  form  a  sort  of  carpet,  is  a 
most  remarkable  variation  which  resulted  from 
a  knaur  or  burr  upon  the  stem  of  a  very  large 
spruce.  It  was  produced  in  the  park  of  Trianon 
at  Versailles. 

Pinus  sylvestris,  nana  monstrosa. 

Produced  from  a  knaur  from  the  stem  of  a 
large  pine.  It  is  dwarf  and  monstrous,  remarka- 
ble for  its  long,  unequal,  crowded  leaves,  and 
by  its  slender,  sometimes  almost  filiform,  irreg- 
ular branches,  which  are  produced  in  such  quan- 


200  BORROWED    OPINIONS. 

tity  that  they  sometimes  completely  conceal  the 
branches  and  even  the  trunk. 

Pinus  sylvestris,  nana  compacta. 

This  variety  is  also  the  result  of  a  knaur  from 
a  large  pine.  It  attains  but  a  foot  or  two  in 
height.  Its  very  short  and  numerous  branches 
have  already  borne  two  crops  of  cones,  some 
nearly  ripe,  small,  though  well  formed,  others 
much  younger,  still  herbaceous. 

Pittosporum  Tobira,  variegatum. 

Populus  Greeca,1  pendula. 

We  cannot  say  whence  this  variety  came  nor 
how  it  was  obtained.  It  has  been  in  cultivation 
very  long.  We  have  a  singular  experience  to 
record  concerning  it.  In  1858  we  grafted  fifteen 
plants  of  P.  nivea  with  P.  Grseca,  and,  seven  of 
the  grafts  growing,  there  was  one  which  produced 
slender  and  drooping  branches  just  like  the  variety 
pendula  of  P.  Graeca,  of  commerce.  This  phe- 
nomenon is  one  of  the  most  curious  which  we 
know.  The  tree  is  planted  in  the  nursery  of  the 
Museum  at  the  side  of  one  of  its  brothers,  to 
which,  physically,  it  bears  almost  no  resemblance, 
although    coming   from   the    same    parent    plant. 

1  Undoubtedly  our  native  large-toothed  aspen,  Populus 
grandidentata.  —  L.  II.  B. 


carriere\s  list  of  bud-varieties.     201 

Both   are   pistillate    and   are   covered   each   year 
with  catkins. 


Potato. 

Potatoes  furnish  many  examples  of  bud-va- 
riation ["mixing  in  the  hill"].  Many  of  our 
cultivated  varieties  are  bud -varieties  from  the 
subterranean  parts.  Every  year  at  digging  time, 
if  we  wish  to  keep  the  varieties  true,  we  are 
obliged  to  throw  out  those  which,  we  say,  are 
"degenerated."  This  so-called  degeneracy  << in- 
stantly tends  to  remove  the  products  from  the 
starting-point,  and  has,  then,  the  result  of  pro- 
ducing new  varieties. 

Modifications  in  potatoes  may  also  occur  in 
the  manner  of  vegetation  or  growth  of  the  under- 
ground parts.  Such  is  the  case  in  the  variety 
called  Pouse-debout  ["  tubers  standing  on  end  "]. 
This  name  was  given  the  variety  because  the 
tubers,  instead  of  lying  horizontally,  or  nearly  so, 
are  placed  upright,  one  against  the  other,  much  as 
small  pieces  of  wood  are  arranged  for  the  making 
of  charcoal. 

The  Marjolin  we  consider  nothing  else  than  a 
peculiarity  of  vegetation.  This  is  proved  by  the 
fact  that  its  characters  —  not  blossoming  and 
maturing  veiy  early —  are  not  constant.  It  has 
produced  two  other  varieties  by  modifications  of 
its  underground  parts.     One  variety  is  the  Mar- 


202  BORROWED   OPINIONS. 

jolin  tardive  [Late  Marjolin],  called  also  Marjolin 
de  deuxieme  Saison,  which  is  sometimes  sold  in 
the  Paris  markets  for  the  Hollande  jamie  [Yellow 
Holland].  It  is  remarkable  for  the  period  of  its 
growth,  which  is  more  prolonged  than  that  of  the 
type,  and  it  is  also  covered  each  year  with  flowers, 
while  its  parent  scarcely  ever  blossoms.  The 
other  variety  has  no  resemblance  to  the  Marjolin 
in  form.  It  is  round,  and  its  sunken  eyes  give 
it  exactly  the  appearance  of  the  ordinary  yellow 
potato.  When  we  cultivated  the  Marjolin  there 
was  not  a  year  when  we  did  not  obtain  round 
ones,  although  we  had  planted  long  ones  very  true 
in  appearance. 

A  very  remarkable  example  of  the  modifications 
furnished  by  the  ordinary  yellow  potato  is  the 
following :  In  a  square  planted  exclusively  with 
this  variety,  very  true  in  appearance,  Ave  gathered 
a  certain  number  of  which  the  skin  was  more  or 
less  dark ;  some  had  yellow  flesh,  others  white. 
Planted  separately,  these  bud-varieties  have  given 
us  potatoes  round  in  form  like  the  parent  type, 
but  among  which  there  were  found  some  entirely 
violet  in  both  exterior  and  interior,  and  some  had 
black  flesh  slightly  marbled  with  white.  This 
modification  of  color  was  not  the  only  change. 
In  some  cases  the  quality  was  very  much  modified. 
Thus,  instead  of  being  nearly  like  the  yellow 
potato,  the  flesh  of  these  varieties  was  compact, 
neither  good  nor  bad. 


carriere's  list  of  bud-varieties.     203 

We  give  two  other  examples  of  bud- variation 
in  potatoes,  observed  by  us  at  the  Museum  in 
18(34 :  Half  of  a  plat  was  planted  with  the  smooth 
long  yellow  called  Hollande,  and  half  with  the 
regular  long  red  commonly  called  Vitelotte  lisse. 
The  first  half  yielded  tubers  similar  to  those 
which  we  had  planted.  The  second  half,  on  the 
contrary,  produced  tubers  differing  from  the  pa- 
rent in  color,  being  of  a  reddish-yellow,  although 
the  form  remained  about  the  same.  The  quality, 
also,  did  not  vary,  so  that  while  we  confounded 
them  sometimes  with  the  Hollande,  we  were  able 
to  distinguish  them  readily  when  cooked,  as 
they  remained  whole,  while  the  others  fell  to 
pieces. 

On  the  end  of  a  plat  where  we  had  planted  fifty 
of  the  ordinary  round  yellow  potato,  one  plant 
grew  until  late  in  the  season  and  gave  round 
potatoes  of  a  deep  red. 

In  this  same  year,  1864,  in  a  square  planted 
entirely  to  Chardon  potato,  we  observed  some 
plants  exactly  similar  to  the  others  in  growth  and 
appearance,  but  which  differed  entirely  in  the 
color  of  the  flowers,  being  dull  white,  a  little 
sulphur-colored,  while  those  of  Chardon  are  violet- 
rose  or  rose-violet.  The  tubers  from  these  white- 
flowered  plants  differed  from  those  of  the  type  in 
being  more  round  and  regular  and  having  less 
pronounced   eyes.     Aside  from  these  variations, 


204  BORROWED   OPINIONS. 

we  have  found  among  the  Chardon  both  earlier 
and  later  varieties,  and  this  in  spite  of  the  fact 
that  we  had  planted  only  such  tubers  as  appeared 
to  be  entirely  true  and  which  for  a  long  time  had 
produced  no  variations  whatever.  Here,  as  in 
the  preceding  cases,  the  modifications  were  from 
the  tubers,  seed  not  having  been  soavii. 

An  instance  similar  to  the  above  is  reported  by 
M.  Joigneaux  in  the  Journal  de  la  Ferme  et  des 
Maisons  de  Campagne :  Nine  or  ten  years  ago  six 
beautiful  tubers  of  a  long,  pale  yellow  potato  were 
given  us.  In  order  to  increase  the  number  of 
hills  we  divided  each  tuber  into  three  pieces.  We 
planted  them  ourselves.  The  cultivating  was  also 
done  by  us.  Some  of  the  potatoes,  a  very  small 
number,  resembled  the  type,  but  the  larger  num- 
ber were  spherical,  some  yellow  like  the  parent, 
others  deep  red. 

All  cultivators  know  that  the  smooth  or  even 
Vitelottes,  whose  eyes  are  few  in  number  and 
scarcely  perceptible,  often  produce  tubers  of  vari- 
ous forms  and  with  eyes  so  much  sunken  that  it 
is  almost  impossible  to  peel  them.  Once  we  ob- 
tained a  variety  which,  besides  the  many  and  deep 
eyes,  produced,  in  considerable  quantity,  agglom- 
erations which  gave  to  the  whole  a  monstrous 
form.  They  were  veritable  hydras.  Although 
coming  from  the  Vitelotte,  which  is  a  good  potato, 
this  variety  was  very  acrid  and  bad. 


carriere's  list  of  bud-varieties.     205 

All  these  examples  show  without  doubt  how 
a  part  of  the  varieties  of  potatoes  are  pro- 
duced, and  proves  that  they  do  not  all  come 
from  seeds.  We  may  convince  ourselves  of  it 
when,  having  observed  the  growth  of  the  plants, 
we  mark  the  peculiar  plants  and  gather  their 
tubers  separately.     See,  also,  page  209. 

The  phenomena  presented  by  potatoes  prove 
that  the  cause  of  the  appearing  of  new  varieties 
is  not  always  due,  as  we  generally  suppose,  to 
crossing,  as  fecundation  can  act  only  upon  the 
seeds.  It  is  also  very  rarely  that  we  practise 
crossing  in  potatoes,  but  we  can  number  the  varie- 
ties by  the  hundred.  But  it  often  happens  that 
cuttings  made  from  portions  of  the  top  of  the  plant 
produce  varieties  different  from  the  parent.  More- 
over, the  existence  of  numerous  varieties  of  certain 
plants  which  we  cultivate  and  which  never  pro- 
duce seeds,  proves  beyond  a  doubt  that  there  are 
causes  aside  from  crossing  which  tend  to  the  pro- 
duction of  new  varieties. 

Primus  Mahaleb,  variegata. 

Aside  from  this  variety,  which  is  very  pretty 
with  its  long  and  very  slender  branches  and 
white-variegated  leaves,  P.  Mahaleb  lias  by  bud- 
variation  given  several  sub- varieties  which  are 
distinguished  by  the  form  of  the  leaves,  and 
especially    by    the    color    of    their    variegations. 


206  BORROWED    OPINIONS. 

Almost  all  these  varieties  are  more  delicate  than 
the  type. 

Rheum  australe,  variegatum. 

Remarkable  for  the  beautiful  white  variegation 
of  the  leaves. 

Ribes  nigrum,  variegatum. 

Leaves  variegated  with  yellowish- white. 

Ribes  rubrum,  variegatum. 

Robinia  hispida,  arborea  and  macrophylla. 

R.  hispida,  var.  arborea  of  the  gardens  (R. 
macrophylla  DC),  differs  from  the  type  by  its 
greater  vigor,  its  branches  very  much  larger, 
the  bark  dark,  glossy,  and  smooth,  and  by  the 
thicker  coriaceous  leaves,  which  are  glossy  as  if 
varnished.  R.  hispida,  var.  macrophylla  of  the 
gardens,  is  nearer  the  type  than  the  last;  it  differs 
from  it,  however,  by  its  greater  vigor,  and  espe- 
cially in  its  flowers,  which,  less  abundant  and  a 
little  more  developed,  are  paler  in  color.  Like 
the  type,  of  which  even  the  origin  is  doubtful, 
these  varieties  do  not  produce  seeds. 

The  fact  of  the  sportive  production  of  the 
variet}r  biennis  upon  R.  hispida  is  wholly  be- 
yond doubt.  Several  times  Ave  have  found  the 
tAvo  sorts  of  twigs  growing  side  by  side  upon  the 
same  branch.     It   is    only  necessary  to  multiply 


carriere's  list  of  bud-varieties.     207 

them  separately  in  order  to  obtain  distinct  varie- 
ties.1 

Robinia  Pseudacacia,  umbraculifera. 

This  plant,  now  so  commonly  used  either  for 
ornament,  under  the  common  name  of  Acacia 
boule,  or  as  a  dwarf  shrub  and  considered  as  a 
forage  plant,  and  called  in  consequence  Acacia  a 
faucher,  comes,  according  to  Turpin,  from  a  knaur 
which  appeared  on  the  stem  of  a  R.  Pseudacacia. 
This  fact  does  not  surprise  us.  It  shows  us  Iioav 
important  these  singular  excrescences  may  become. 

Rose  Eglanteria,  punicea. 

This  differs  from  the  ordinary  yellow-flowered 
capucine  rose  (R.  Eglanteria)  in  the  color  of  the 
flowers,  which  is  an  orange-red.  In  many  soils 
this  variety  returns  more  or  less  quickly  to  the 
type.  It  frequently  happens  that  we  may  see 
even  upon  the  same  stem  a  red  and  a  yellow 
flower.  Sometimes  we  find  a  flower  winch  pre- 
sents these  colors  separately  on  opposite  sides  and 
of  nearly  equal  extent,  or  some  petals  may  be  half 
red  and  half  yelloAV.  In  general,  the  sport  is  less 
vigorous  than  the  type,  so  that  under  the  influ- 

1  Plants  of  normally  thorny  species  are  often  found  which 
bear  no  thorns.  There  is  a  so-called  variety  inermis  of  the 
honey-locust,  Gleditschia  triacanthos.  Wild  blackberries  with 
smooth  canes  are  occasionally  found.  In  fact,  most  prickly  or 
thorn-bearing  plants  vary  much  in  these  characters.  —  L.  H.  B. 


208  BORROWED    OPINIONS. 

ence  of  a  slow  modification  Ave  sometimes  see  the 
color  gradually  disappear,  and  at  the  end  of  a 
certain  time  we  have  a  rose  with  completely  yel- 
low flowers  in  the  place  where  we  planted  one 
with  orange-red  flowers. 

For  further  notes  on  the  rose,  see  pages  161  to 
170. 

Salix  Babylonica,  annularis. 

Very  remarkable  for  the  form  of  its  leaves. 
For  a  long  time  we  have  noticed  it  showing  itself 
each  year  upon  an  old  tree.  The  parts  upon 
which  it  appeared,  being  generally  weak,  pro- 
duced, instead  of  long,  linear,  plane  leaves,  those 
which  were  rolled  up  on  the  edges  and  distorted 
into  rings.  It  is  very  constant.  We  have  no 
examples  of  its  reverting.  It  is  much  less  vigor- 
ous than  the  type. 

Sambucus   nigra,   variegata   aurea   and  variegata 

argentea. 

These  two  varieties  differ  from  the  species  in 
the  variegation,  which  is  made  by  yellow  in  the 
first,  white  in  the  second.  The  second  is  much 
less  vigorous  than  the  type. 

Sambucus  nigra,  monstrosa. 

Analogous  to  Euonymus  Japonica,  f  asciata.  The 
flowers  are  also  monstrous,  and,  up  to  this  time, 
the  seeds  which  they  have  produced  have  always 
been  poor. 


CARRIERE'S   LIST   OF   BUD- VARIETIES.       209 

Solanum  Dulcamara*  variegatum. 

Solanum  tuberosum,  variegatum. 

Remarkable  for  its  yellow- variegated  stems  and 
leaves.  During  the  year  previous  to  the  appear- 
ing of  this  variety,  its  parent  type  presented  no 
unusual  characters.     See  Potato,  page  201. 

Spiraea  Ulmaria,  variegata. 

Symphoricarpus  vulgaris,  variegata. 

Symphytum  officinale,  variegatum. 

Thuyopsis  dolibrata,  variegata. 

This  variety,  of  which  the  leaves  are  variegated 
with  white,  is  remarkable  for  its  vigor  and  its 
facility  for  forming  heads  when  multiplied  by 
cuttings. 

Ulmus  campestris,  variegata,  argentea,  aurea  picta, 

etc. 

Variegated  varieties  of  the  common  elm  are 
numerous.  They  are  distinguished  both  by  the 
color  and  form  of  the  variegations. 

Viburnum  Opulus,  sterilis  or  Boule  de  neige. 

Viburnum  Opulus,  sterilis  variegatum. 

Viburnum  Keteleerii,  macrocephalum. 

Analogous  to  the  sterile  varieties  of  V.  Opulus. 


210  BORROWED    OPINIONS. 

Viburnum  Tinus,  variegatum. 

Viola  Rothomagensis,  pallida. 

This  variety,  of  which  the  two  superior  petals 
are  pale  lilac  and  spotted,  while  the  three  others 
are  yellowish-white  and  lightly  striped,  was  pro- 
duced by  bud- variation  at  the  Museum. 

We  have  said  elsewhere  that  the  phenomena  of 
bud-variation  could  be  divided  into  two  classes, 
one  group  including  those  variations  which  appear 
abruptly,  the  other  those  which  take  place  slowly. 
This  violet  falls  under  the  latter  group.  In 
1863  we  received  from  the  hills  of  Vernon  a 
certain  number  of  plants  of  V.  Rothomagensis. 
Planted  at  the  Museum,  they  preserved  nearly  all 
their  characters  except  the  villosity,  which  in  large 
part  disappeared  the  first  year.  During  this  year 
1863  and  the  entire  year  1864,  they  produced  blue 
flowers  abundantly.  In  the  winter  of  1864-65  all 
the  plants  perished  except  one.  The  remaining 
plant,  instead  of  being  covered  with  beautiful 
blue  flowers  as  it  had  been  the  two  preceding 
years,  produced  flowers  almost  white.1 

Vine  (Grape). 

Bud- variation  is  comparatively  common  in  the 
vine.       [Frequent    cases  occur   in   the  American 

1  This  variation  appears,  after  all,  to  have  been  an  abrupt 
one.  —  L.  H.  B. 


CARRIERE   ON   GRAPE   SIM  HITS.  211 

grapes.]  It  is  well  understood  in  this  case,  as 
the  vine  is  one  of  the  oldest  of  cultivated  plants 
and  it  is  multiplied  almost  always  by  cuttings; 
and  as  cuttings  are  made  by  millions  each  year 
a  bud-variety  soon  becomes  widely  disseminated. 
It  frequently  happens  that  a  shoot  Avill  produce 
grapes  differing  in  form  or  color  from  those  which 
are  borne  upon  other  shoots  of  the  same  vine.  We 
may  add  that  these  variations  nearly  always  pre- 
sent peculiar  qualities  also.  We  will  cite  ex- 
amples. 

Upon  a  plant  of  black-fruited  Muscat  grape  we 
have  observed  for  several  years  that  some  shoots 
produce  white  grapes. 

The  white  seedless  Corinth  is  a  bud-variety 
from  a  variety  which  has  much  larger  fruits,  with 
seeds.  This  is  a  fact  which  we  have  several  times 
observed  upon  bunches  where  some  fruits  were 
unusually  developed  and  which  contained  seeds. 
The  white  Cornith  is  analogous  to  the  Chasselas 
de  Demoiselles. 

A  proprietor  of  large  vineyards  in  the  middle 
of  France,  the  late  Cazalis  Allut,  wrote  some  years 
ago  as  f  oIIoavs  :  — 

"  A  stock  of  Teret  produced  with  me,  for  sev- 
eral years,  black  grapes  upon  shoots  of  two  of 
its  arms,  and  gray  grapes  upon  shoots  of  the  other 
arms.  A  stock  of  Epiran  gris,  trained  in  cordon, 
is  now  about  forty  feet  long.     The  first  twenty 


212  BORROWED    OPINIONS. 

feet  produces  constantly  gray  grapes  and  the  re- 
mainder produces  white  ones.  I  have  in  an 
enclosure  a  stock  of  Epiran  noir  having  several 
arms.  The  shoots  of  one  of  the  arms  give  grapes 
almost  twice  as  large  as  those  on  other  parts  of 
the  vine." 

Another  viticulturist,  M.  Henri  Bouschet  of 
Montpellier,  wrote  very  recently:  — 

"  I  had  occasion  for  several  years  to  see  in  my 
collection  at  Lot-et-Garonne,  a  plant  of  Prunella 
gris,  which,  sometimes  upon  one  stem,  sometimes 
upon  two,  bore  black  grapes,  while  the  remainder 
of  the  vine  bore  gray  ones.  I  have  noticed  for 
two  years  in  my  collection  at  Calmelte  a  most 
curious  fact  upon  three  grafts  of  a  Spanish  va- 
riety which  came  to  me  from  the  collection  of 
Luxembourg,  where  it  is  called  Parrel  del  Reyno 
de  Lorca  and  which  I  have  recognized  as  our 
Morastel  noir.  One  of  these  three  stocks  has 
borne  on  one  side,  to  my  great  surprise,  black 
grapes  similar  to  those  of  the  Morastel,  and  upon 
the  other  side,  constantly,  white  bunches  having 
an  appearance  very  different  from  an  ordinary 
white  Morastel,  and  presenting  a  foliage  very 
different  in  size  and  form.  This  odd  foliage  ap- 
pears to  me  to  be  identical  with  that  of  the  Oyo 
de  Rey  de  Morada,  of  which  the  bright  yellow- 
ish-green leaves  present  very  shallow  rounded 
dentate  lobes,  while  the  leaves  of  the  Morastel  are 


CARRIE  1 J  H    ON    GRAPE   SPORTS.  213 

deep  green  with  deep  divisions,  the  lobes  acute, 
with  teeth  detached  and  terminating  in  a  point." 

A  passage  which  we  find  in  the  Parfait 
Vigneron  (edition  of  1811)  seems  to  confirm  the 
opinions  which  we  give  concerning  bud- variations 
in  grapes :  — 

"  A  citizen  of  Vilmorin  has  observed  a  stock  of 
Meunier  to  bear,  upon  some  shoots,  leaves  and 
fruits  of  Maurillon  precoce.  A  citizen  of  Ju- 
milhac  has  seen  likewise  the  Meunier  become 
Maurillon." 

Therefore  the  grape  called  Madeleine  Juillet, 
Maurillon  hatif,  etc.,  is  only  a  sport  from  Meunier, 
a  fact  which  shows,  as  we  have  said  before,  that 
the  varieties  produced  by  bud-variation  may  pre- 
sent qualities  different  from  those  presented  by 
the  plants  from  which  they  come. 

Upon  a  plant  of  Pinot  gris  there  appeared  at 
the  Museum  in  1863  a  shoot  whose  leaves  were 
much  variegated  or  striped  with  yellow.  It 
produced  a  grape  very  similar  to  the  variety  from 
which  it  came.  It  appeared  to  be  much  less  fer- 
tile, however. 

In  1863  we  observed  two  other  very  remarkable 
examples.  One  example  concerns  the  Precoce 
Malingre,  the  other  the  variety  designated  by 
the  name  of  Verjus.  These  examples  present 
contrary  results.  Thus,  while  Precoce  Malingre 
has  long,  oval,  scattered  fruits,  and  the  bud- variety 


214  BORROWED   OPINIONS. 

which  appeared  upon  it  had  round  fruits  borne 
close  together  and  larger  than  those  of  the  type, 
the  Verjus  has  slightly  oblong  or  nearly  spherical 
fruits  and  the  bud-variety  which  was  developed 
upon  it  had  fruits  long-oval  and  attenuated  at 
both  ends,  and  somewhat  later  than  those  of  the 
type. 

The  Chasselas  gros  Coulard  is  a  bud-variety 
which  appears  frequently  upon  the  ordinary 
Chasselas.  Its  fruits  are  large  and  spherical. 
They  often  drop.  It  differs  especially  from  the 
Chasselas  by  its  stronger  shoots  with  joints 
much  closer  together,  and  by  its  leaves  being 
less  lobed,  a  little  longer  and  thicker,  of  a 
glossy  green  as  if  varnished.  It  differs  also 
from  the  ordinary  Chasselas  in  its  temperament. 
It  needs  much  heat  and  also  shelter  from  the 
influence  of  the  air.  It  generally  succeeds  well 
in  forced  culture. 

The  Chasselas  de  Demoiselles,  remarkable  for 
its  fruits,  which  are  scarcely  larger  than  shot,  is  a 
bud-variety  from  the  ordinary  Chasselas.  This 
phenomenon  appears  to  be  due  to  the  partial  abor- 
tion of  the  sexual  organs  and  particularly  of  the 
anthers,  whence  results  the  lack  of  impregnation 
of  the  flowers  and  the  consequent  abortion  of  seeds. 
Propagated  by  cuttings,  it  preserves  its  characters. 
A  variety  with  variegated  leaves  has  appeared 
from  the  ordinary  Chasselas. 


FOCKE    ON    THE    PRIMARY   CROSS.  215 

Wigandia  Caracassana,  variegata. 

Distinct  by  its  leaves  and  even  its  branches 
being  variegated  with  white.  The  variety  ap- 
peared in  1862  upon  a  plant  which,  placed  in  the 
open  air  at  the  beginning  of  the  season,  presented 
no  unusual  characters. 

III.     Focke's  Discussion  of  the  Character- 
istics  of  Crosses.     (Translation  of  Chapter 
IV.   of  Die  Pflanzen-Mischlinge.1) 
There  is  no  absolute  distinction  between  plants 
of  a  pure  and  those  of  a  .hybrid  or  mixed  descent; 
there   are  therefore  no  signs  by  which  one  can, 
under  all  circumstances  and  with  certainty,  rec- 
ognize  the    mongrel  nature    of   a   certain   plant. 
Hybrids,    nevertheless,    often    sIioav   a    series    of 
characteristics   which    indicate    with    greater    or 
less  accuracy  their  mixed  descent.     Certain  rules 
can  be  made  in  regard  to  them,  of  which  none, 
of  course,  is  without  exception. 

I.    THE  SIMPLE  PRIMARY  CROSS   (AxB).2 

1.  All  individuals  formed  by  the  crossing  of 
tivo  pure    species  or  races  are,  if  they  have  been 

iFocke  uses  the  word  mischling  (derived  from  mischen,  "  to 
mix  ")  in  about  the  same  sense  in  which  we  use  the  noun  cross  ■ 
i.e.  it  is  a  generic  term  for  both  cross-breeds  and  hybrids. 

2  In  these  formulas,  the  letters  are  used  to  designate  the 
parents  of  any  cross.    In  common  with  usage  amongst  botanists, 


216  BORROWED    OPINIONS. 

produced  and  grown  under  the  same  conditions, 
exactly  like  each  other,  as  a  rule,  or  they  differ 
hardly  more  than  specimens  of  one  and  the  same 
species  are  apt  to  do. 

This  carefully  stated  proposition,  founded  upon 
experience,  appears  to  be  sufficiently  justified  by 
numerous  experiments,  but  it  is,  nevertheless, 
subject  to  many  exceptions.  Some  students  of 
crosses  have  so  limited  its  application  that  they 
dared  only  to  assert  the  similarity  of  the  speci- 
mens obtained  from  a  capsule  fertilized  by  the 
same  plant.  At  all  events,  the  rule  proves  itself 
to  a  certain  degree  trustworthy  only  in  those 
cases  in  which  the  similarity  of  origin  and  con- 
dition of  growth  demanded  by  the  terms  of  the 
rule  are  really  present. 

The  question  easiest  to  answer  is  just  the  one 
about  which  there  has  been  the  most  violent  dis- 
cussion, namely,  that  relating  to  the  stronger 
influence  of  the  one  or  the  other  sex  upon  the 
offspring.  The  crosses  of  the  two  species  or  races 
A  and  B  resemble  each  other  whether  A  was  male 
or  female  in  the  crossing.  Experimenters,  es- 
pecially Kolreuter,  Gartner,  Naudin,  and  Wichura, 
have  not,  on  the  whole,  been   able    to  find   any 

arbitrary  signs  are  used  in  the  text  to  designate  the  sex  of  each 
parent.  The  sign  $  represents  the  male,  or  the  parent  which 
furnished  the  pollen  ;  9  stands  for  the  female  or  seed-hearing 
parent.  — L.  H.  B. 


FOCKE   ON   THE   PRIMARY   CROSS.  217 

difference  between  A  9  x  B  $  ,  and  13  9  x  A  $  . 
More  than  one  hundred  years  had  passed  since 
Kolreuter  had  proved  the  conformity  of  Nicotiana 
rustica  9  x  panicnlata  $ ,  and  N.  paniculata  9  X 
rnstica  $ ,  when  one  of  the  acutest  florists  of  our 
time,  Timbal-Lagrave,  was  also  astonished  in  the 
highest  degree  by  a  similar  experience.  All  the 
rules  and  supposed  experiences  according  to  which 
the  florists  were  to  know,  from  the  morphological 
characteristics  of  a  hybrid,  which  of  the  progeni- 
tors had  furnished  the  pollen  for  its  formation, 
and  which  had  borne  the  seed,  are  entirely  ground- 
less and  foolish.  Besides,  it  has  been  proved  by 
many  experiments,  that  in  the  vegetable  kingdom, 
with  regard  to  species,  as  a  rule,  the  form-deter- 
mining power  of  the  male  and  female  elements  in 
the  progeny  is  entirely  equal. 

As  with  all  other  rules  touching  the  crossing  of 
plants,  this  one  of  the  similarity  of  the  products 
of  reciprocal  crossings  is  not  without  its  excep- 
tions. It  is  a  matter  of  course  that  an  observed 
difference  can  be  ascribed,  with  any  probability, 
only  to  a  stronger  influence  of  the  male  or  female 
elements,  provided  that  the  experiments  are  car- 
ried on  in  exactly  the  same  manner,  and  if  they 
always  lead  to  the  same  result  after  repeated 
trials.  So  far,  almost  all  the  recorded  experi- 
ments could  be  improved  in  this  respect,  for  they 
are   open   to    justifiable    doubt.      The    following 


218  BORROWED    OPINIONS. 

declarations  of  the  differences  in  the  products  of 
reciprocal  crossing  seem  worthy  of  notice. 

a.  The  influence  of  the  female  element  in  Pe- 
largonium fulgidum  x  grandiflorum,   P.  peltatum 

X  zonale,  Epilobium  hirsutum  x  Tournefortii,1  ex- 
ceeds that  of  the  male  as  regards  general  form. 
This  influence  is  also  shown  more  strongly  in  the 
colors  of  the  flowers  of  several  hybrids  of  Dig- 
italis, in  some  also  in  the  form  of  the  corolla.  In 
Nymphaea  rubra  x  dentata,  the  seed-leaves  resemble 
those  of  the  female  progenitors. 

b.  The  female  element  shows,  apparently,  an 
overpowering  influence  in  the  power  of  with- 
standing cold  in  the  Rhododendron  (hybrids  of 
R.  arboreum),  Lycium,  and  perhaps  also  in  Cri- 
niim  (hybrids  of  C.  Capense). 

c.  The  male  element  influences  the  general 
form  especially  in  Papaver  Caucasicum  x  somni- 
ferum,  and  Cypripedium  barbatum  x  villosuin  (if 
constant  ?)  ;  it  shows  a  stronger  influence  upon 
the  colors  of  the  flower  in  Petunia. 

d.  Gartner  says  that  he  has  sometimes  observed 
differences  in  the  fruitfulness  and  progeny  of  re- 
ciprocal hybrid  forms,  e.g.  in  Dianthus  barbatus 
X  superbus.     The  experiences  of  Gartner  should, 

however,  hardly  suffice  to  establish  the  uniformity 
of  this  occurrence. 

The  principal  differences  between  A  ?   and  B  $ 

1  The  various  examples  cited  in  the  text  are  fully  explained 
in  the  body  of  Focke's  work,  Die  Pflanzen-Mischlinge. 


FOCKE   ON   THE   PRIMARY   CROSS.  219 

and  B  9  and  A  $  ,  have  been  observed  by  Kolreuter 
and  Gartner  in  some  Digitalis  hybrids.  That 
these  differences  really  show  themselves  each  time 
and  in  the  same  manner,  is  by  no  means  proved. 

Much  oftener,  the  departures  from  the  regular 
uniformity  of  single  specimens,  observed  among 
hybrids,  are  entirely  independent  of  the  influence 
of  the  species  in  the  hybrid  formation.  Often 
important  differences  appear  among  the  seedlings 
of  the  same  cross  which  have  been  treated  exactly 
alike.  These  differences  show  themselves  in  dif- 
ferent ways :  — 

1.  Single  specimens  of  the  cross  may  show  but 
slight  differences  among  themselves,  especially  in 
the  color  of  the  blossoms  and  similar  character- 
istics, which  are  easily  changed ;  compare,  for 
example,  the  hybrids  of  Verbascum  phoeniceum, 
Salix  Caprea  x  daplmoides. 

2.  The  cross  may  appear  in  two  different  types, 
each  of  which  represents  a  different  combination 
of  the  characteristics  of  the  progenitors.  As  a 
rule,  one  type  more  closely  resembles  the  one,  and 
the  second  the  other  progenitor;  the  numbers  of 
the  two  types  are  often  very  unequal.  Gartner 
designated  the  rarer  forms  "  exceptional  types " 
(AuBnahmetypus).  For  examples,  study  Cistus, 
Dianthus,  Geum,  Oenothera,  Lobelia,  Verbascum 
Thapsus  x  nigrum,  Nicotiana  quadrivalis  x  Taba- 
cum,  var.  macrophylla. 


220  BORROWED    OPINIONS. 

3.  The  cross  may  appear  in  several  different 
types.  Gartner  gives  some  examples  of  these, 
although  in  his  cases  it  is  probably  a  question  of 
three  known  forms  of  one  polymorphous  union. 

4.  The  cross  may  appear  in  a  typical  interme- 
diate form,  and  a  number  of  vacillating  ones 
approaching  one  or  the  other  parent,  and  among 
which  no  distinct  type  can  be  distinguished. 
Such  is  Medicago  falcata  x  sativa,  usually  also 
Melandrium  album  x  rubrum. 

5.  The  cross  may  have  from  the  beginning 
very  many  forms.  The  experiments  which  have 
been  made  leave  it  doubtful  if  in  these  cases  one 
or  more  constant  types,  with  a  similar  combina- 
tion of  characteristics,  can  be  distinguished  among 
the  vacillating  forms.  Study  Abutilon,  hybrids 
of  Pelargonium  glaucum,  P.  radula  x  myrrhi- 
folium,  Passiflora,  Hieracium,  Nepenthes,  Narcis- 
sus. Gartner  made  the  assertion  that  hybrids 
between  two  species  are  of  similar  form,  whilst 
crosses  of  varieties  are  polymorphous.  If,  by  va- 
rieties, is  understood  the  unsettled  garden  forms 
or  garden  crosses,  then  the  remark  is  justifiable  ; 
but  if  fixed  races  of  pure  descent  are  also  included, 
then  it  is  decidedly  wrong.  See  "  Cross-breeds 
and  Hybrids"  (section  III.,  page  247). 

Entirely  different  results  are  obtained  by  com- 
paring hybrids  which,  although  springing  from 
the  same   species,   were  produced  and  grown  in 


FOCKE   ON   THE   PRIMARY   CROSS.  221 

different  places.  Spontaneous  hybrids  are,  as  a 
rule,  much  more  variable  than  those  produced 
artificially,  e.g.  Verbascum  Lychnitis  x  Thapsus 
and  V.  Lychnitis  x  nigrum.  My  hybrids  between 
Digitalis  purpurea  and  D.  lutea  resembled  each 
other  much  when  I  had  sown  the  seeds ;  on  the 
other  hand,  very  different  forms  arose  when  the 
seeds  had  accidentally  sown  themselves.  It  may 
be  that  in  this  case  there  was  no  real  causative 
connection  between  the  many  forms  and  the  man- 
ner of  sowing ;  nevertheless  it  is  certain  that 
several  growers  have  very  often  obtained  different 
results  in  their  crossings  from  the  same  species. 
The  uniformity  of  all  the  products  of  the  same 
crossing,  which  undoubtedly  is  the  rule  with  the 
experiments  of  growers,  appears  in  nature  rather 
to  be  the  exception  than  the  rule.  It  remains  to 
be  ascertained  what  influence  the  unequal  nour- 
ishment of  the  parent  species,  or  of  the  hybrid 
seedlings,  has  upon  the  variability  of  the  hybrids. 

2.  The  characteristics  of  the  crosses  may  be  differ- 
ent from  the  characteristics  of  the  parent  species. 
It  is  in  size  and  luxuriance  (see  proposition  3),  as 
ivell  as  hi  their  sexual  ability  (see  proposition  4), 
that  they  differ  most  from  both  parent  sjiecies. 

The  manner  differs  in  which  the  characteristics 
of  the  parent  species  are  united  in  the  cross. 
Generally,  a  blending  or  mutual  union  takes 
place,  but   often  in  such  a  manner  that  in   one 


222  BORROWED    OPINIONS. 

respect  one,  and  in  another  respect  the  other 
parent  seems  to  appear.  Sometimes,  for  example, 
the  cross  resembles  one  parent  in  the  leaves,  and 
the  other  parent  in  the  flower.  Sometimes  there 
appears  a  variety  of  the  cross,  in  which  the  char- 
acteristics are  distributed  in  the  reverse  order. 
Some  crosses  resemble  at  first  one  species,  and 
later  the  other  parent  species ;  as  their  leaves 
show  in  the  spring  the  one  and  in  the  fall  the 
other  type  (Cistus,  Populus);  or  the  colors  of 
the  flowers  change  during  the  blossoming  (Melan- 
drium  album  x  rubrum,  Epilobium  roseum  x 
montanum  ;  compare  also  Lantana),  or  in  the  fall 
(Nicotiana  rustica  x  Tabacum,  Tropseolum,  Lobe- 
lia, etc.),  also  sometimes  in  different  years  (Bletia 
crispa  x  cinnabarina,  Galium  cinereum  x  verum) . 
By  the  union  of  races  (rarely  in  hybrids  in  the 
more  restricted  sense  of  the  term),  one  finds, 
among  other  things,  the  characteristics  of  the  par- 
ent species  unmixed  beside  each  other  (compare 
Cucumis  Melo,  the  thorniness  of  the  Datura 
fruits,  color  of  the  flower  in  Rhododendron  Rho- 
dora  x  calendulaceum,  R.  Ponticum  x  flavum, 
Anagallis,  Linaria  vulgaris  x  purpurea,  Calceo- 
laria, Mimulus,  Mirabilis).  The  colors  of  the 
flower  often  appear  in  an  unexpected  and  unex- 
plainable  manner  :  the  hybrids  of  Verbascum 
phceniceum  are  very  variable  in  the  colors  of 
the  flowers,  and  in  other  respects  quite  uniform; 


FOCKE    ON    THE   PRIMARY    CROSS.  223 

on  the  hybrids  of  Helianthemum  have  sometimes 
been  found  differently  colored  flowers  on  the 
same  stalk,  at  the  same  time. 

From  the  crossing  of  closely  related  races, 
especially  varieties  in  color,  there  often  appear 
plants  which'  exactly  or  very  closely  resemble  the 
parent  types;  compare  Brassica  Rapa,  var.,  Linum, 
Pisum,  Fhaseolus  ;  Anagallis,  Atropa,  Datura 
Stramonium,  Salvia  Horminum,  etc.  Usually 
the  influence  of  the  second  parent  race  does  not 
show  itself  till  the  second  generation;  and,  in 
fact,  in  such  a  manner  that  a  part  of  the  seed- 
lings return  to  that  form,  either  entirely  or  only 
in  certain  respects.  Only  in  Atropa,  no  return 
to  the  (slightly  fixed)  yellow  form  has  been 
observed. 

In  some  cases,  the  cross  resembles  one  of  the 
parent  forms  so  much  that  it  could  be  considered 
as  only  a  slight  variation  of  the  same.  Even  in 
crosses  between  two  considerably  different  species, 
the  predominating  influence  of  one  parent  species 
is  sometimes  shown  in  a  striking  degree.  The 
hybrid  of  Dianthus  Armeria  x  deltoides  resem- 
bles D.  deltoides  much  more  than  the  other 
parent  species ;  of  D.  Caryophyllus  x  Chinensis 
resembles  D.  Caryophyllus  ;  of  Melandrium  ru- 
brum  x  noctiflorum  resembles  M.  rubrum  ;  of  Ver- 
bascum  Blattaria  x  nigrum  resembles  V.  nigrum  ; 
of  Digitalis  lutea  x  purpurea  resembles  D.  lutea. 


224  BORROWED    OPINIONS. 

Sometimes  even  the  primary  hybrids  show 
characteristics  which  are  entirely  different  from 
either  parent  species  ;  especially  is  this  the  case, 
amongst  other  things,  in  the  colors  of  the  flowers. 
The  most  curious  is  the  regularly  blue-flowering 
hybrids  of  the  white  Datura  ferox  with  the 
equally  white  D.  he  vis  and  D.  Stramonium, 
var.  Bertolonii.  There  are  many  examples  of 
unexpected  coloring  of  the  blossoms  of  hybrids 
from  species  of  colored  flowers,  while  the  crosses 
by  no  means  always  show  the  shades  of  color 
which  would  be  obtained  by  a  mixture  of  the 
parental  pigments.  Noticeable  instances  are 
shown,  e.g.,  by  Clematis  recta  x  integrifolia,  Aqui- 
legia  atropurpurea  x  Canadensis  (and  others), 
Nicotiana  suaveolens  x  glutinosa,  Verbascum 
pulverulentum  x  thapsiforme,  hybrids  of  V. 
phceniceum,  Anemone  patens  x  vernalis,  Be- 
gonia Dregei  x  Sutherlandi  (and  others).  In 
the  crosses  of  races,  e.g.,  of  Papaver  somniferum 
and  Datura  Stramonium,  many  characteristics 
appear  which  belong  not  to  the  parent  forms,  but 
to  other  races  of  the  same  species.  Nicotiana 
rustica  x  paniculata  sometimes  shows  the  colors 
of  the  blossoms  of  N.  Texana,  a  foreign  sub- 
species of  N.  rustica.  Other  characteristics 
which  the  hybrids  show  in  a  greater  degree  than 
the  parent  forms,  are,  e.g.,  the  greater  stickiness 
of  some  hybrids  of  Nicotiana  (rustica  x  paniculata). 


FOCKE   ON   THE   PRIMARY   CROSS.  225 

the  apparently  greater  wealth  of  honey  in  N. 
rustica  x  paniculata,  the  stronger  nauseous  odor 
of  the  hybrids  of  Melandrium  viscosum,  the 
supposed  increase  in  the  quantity  of  quinine  (?) 
in  hybrids  of  Cinchona  (according  to  Kuntze). 

In  later  generations  of  hybrid  growth,  devia- 
tions from  the  characteristics  of  the  parent  species 
are  much  oftener  observed. 

3.  Crosses  of  different  races  and  species  are  dis- 
tinguished from  plants  of  a  pure  race,  as  a  rule, 
by  the  poiver  of  vegetation.  Hybrids  between  very 
different  species  are  often  very  weak,  especially 
when  young,  so  that  it  is  difficult  to  successfully 
raise  the  seedlings.  On  the  other  hand,  crosses  of 
more  closely  related  species  and  races  are,  as  a 
rule,  uncommonly  luxuriant  and  strong ;  they  are 
distinguished  mostly  by  size,  rapidity  of  growth, 
early  flowering,  abundance  of  flowers,  longer  life, 
stronger  reproductive  power,  unusual  size  of  some 
special  organs,  and  like  characteristics. 

For  a  closer  confirmation  of  this  proposition,  it 
will  be  to  the  purpose  to  refer  to  some  examples. 
Delicate  seedlings  are  mentioned,  e.g.,  in  Nym- 
phsea  alba  crossed  with  foreign  species,  Hibiscus, 
Rhododendron  Rhodora  with  other  species,  R. 
Sinense  with  Eurhododendron,  Convolvulus,  poly- 
phyllons  Salix  hybrids,  Crinum,  Narcissus.  The 
experience  that  seedlings  of  hybrid-fertilized  seeds 
are  delicate,  is  frequent.     A  dwarfish  growth  has 


226  BORROWED    OPINIONS. 

rarely  been  observed  in  hybrids,  although  there 
are  some  instances  of  it.  Large  growth  is,  on  the 
other  hand,  much  more  common,  e.g.,  Lycium 
Datura,  Isoloma,  Mirabilis.  Usually  the  hybrids 
exceed  in  height  both  parent  species,  or  at  least 
their  medium  height ;  compare,  e.g.,  many  hybrids 
of  Nicotiana,  Verbascum,  Digitalis.  The  vege- 
tation sometimes  takes  place  exceedingly  fast. 
Klotzsch  emphasizes  the  rapid  growth  of  his 
hybrids  of  Ulmus,  Alnus,  Quercus,  and  Pinus. 
The  flowering  time  often  comes  earlier  than  in 
the  parent  species,  e.g.,  in  Papaver  dubium  x 
somniferum,  some  Dianthus  hybrids,  Rhododen- 
dron arboreum  x  Catawbiense,  Lycium,  Nicotiana 
rustica  x  paniculata,  Digitalis,  Wichura's  six-fold 
Salix  hybrid,  Gladiolas,  Hippeastrum  vittatum  x 
Regime,  etc.,  but  especially  in  many  hybrids  of 
Verbascum.  On  the  other  hand,  there  are,  no 
doubt,  also  single  hybrids  which  blossom  only 
after  a  long  period,  or  not  at  all,  e.g.,  in  the  genera 
Cereus  and  Rhododendron.  Only  one  example 
of  earlier  maturity  of  seeds,  independent  of  an 
earlier  maturing  of  the  blossoms,  is  known  to  me, 
namely,  in  Nuphar.  Very  often  and  very  com- 
monly an  extraordinary  abundance  of  flowers  has 
been  observed  in  hybrids  ;  compare,  e.g.,  Capsella, 
Helianthemum,  Tropaeolum,  Passiflora,  Begonia, 
Rhododendron,  Nicotiana  (rustica  x  paniculata, 
glutinosa  x  Tabacum,    and    others),    Verbascum, 


FOCKE   ON   THE   PRIMARY   CROSS.  227 

Digitalis,  many  Gesneracese,  Mirabilis,  Cypripe- 
dium.  The  size  of  the  blossoms  is  often  increased 
in  hybrids;  in  a  cross  of  two  species  with  different 
sized  flowers  it  is  not  rare  that  the  flowers  of  the  hy- 
brid attain  the  size  of  those  of  the  larger-flowered 
parent,  or  almost  that  size.  Dianthns  arenarins  x 
snperbns,  Rnbns  ceesius  x  Bellardii,  hybrids  of  Rosa 
Gallica,  Begonia  Boliviensis,  Isoloma  Tyda3um, 
give  examples  of  uncommonly  large  flowers. 

A  strong  vegetative  reproductive  power  is  very 
common  among  hybrids  ;  compare,  e.g.,  Nymphsea, 
hybrids  of  Rubus  cresius,  Nicotiana  suaveolens  x 
Tabacum,  var.  latissima,  Linaria  striata  x  vulgaris, 
Potamogeton.  A  longer  life  is  especially  notice- 
able in  some  hybrids  of  Nicotiana  and  Digitalis. 
A  greater  power  of  resistance  against  cold  is  also 
noticeable  in  Nicotiana  suaveolens  x  Tabacum,  var. 
latissima,  while  Salix  viminalis  x  purpurea  is  said 
to  be  more  sensitive  to  frost  than  either  of  the 
parent  species. 

These  facts  indicate  partly  a  certain  loss  of 
vigor  which  is  inherent  to  the  hybrids  on  account 
of  their  abnormal  descent,  and  partly,  on  the  con- 
trary, an  exceptional  vegetative  power.  This 
latter  fact,  which  occurs  much  oftener  than  the 
former,  has  only  lately  been  elucidated  to  any 
extent.  The  important  experiments  of  Knight, 
Lecoq,  and  others,  had  been  known  for  some  time, 
but  only  through  the  careful  researches  of  Charles 


228  BORROWED    OPINIONS. 

Darwin  has  the  favorable  influence  of  a  cross 
between  different  individuals  and  races  of  one 
and  the  same  species  been  clearly  shown.  The 
strengthening  of  the  vegetative  power  in  some 
hybrids  is  evidently  a  universal  experience  which 
needs  no  special  explanation,  on  account  of  the 
peculiar  circumstances  of  the  formation  of  the 
hybrids.  It  was  formerly  thought  that  the  di- 
minished sexual  fruitfulness  is  compensated  by  a 
greater  vegetative  luxuriance,  a  statement  the 
untenableness  of  which,  as  Gartner  showed,  is 
most  plainly  shown  by  the  fact  that  many  of  the 
most  fruitful  crosses  (Datura,  Mirabilis)  are  also 
distinguished  by  an  enormous  growth. 

4.  Hybrids  of  different  species  often  form  in  their 
anthers  a  smaller  number  of  normal  pollen  grains, 
and  in  their  fruits  a  smaller  number  of  normal  seeds, 
than  plants  of  a  pure  descent ;  sometimes  they  pro- 
duce neither  pollen  nor  seeds.  In  crosses  of  nearly 
related  races,  this  weakening  of  the  sexual  organs 
does  not  occur  as  a  rule.  The  blossoms  of  sterile  or 
slightly  fruitful  hybrids  usually  remain  fresh  for 
a  long  time. 

No  characteristic  of  hybrids  has  received  more 
attention  than  the  diminution  of  the  sexual  power 
which  has  been  observed  in  them.  Even  Kolreuter 
believed  that  this  characteristic  permitted  the 
drawing  of  a  sharp  line  between  species  and  vari- 
eties.    The  same  thought  has  prevailed  amongst 


FOCKE    ON    THE   PRIMARY   CROSS.  229 

botanists  to  a  great  extent  since  then,  and  even 
in  very  recent  times  Naudin,  Decaisne,  and  Cas- 
pary  have  defended  the  ideas  of  Kolreuter  in  a 
more  or  less  modified  form.  Knight,  Klotzsch, 
and  formerly  also  Gordon,  considered  the  pollen 
of  hybrids  to  be  entirely  impotent,  a  vieAv  which 
was  even  then  contradicted  by  the  accurate  ex- 
periments of  Kolreuter.  It  has  often  been  wrongly 
declared  that  Kolreuter  had  himself  spread  the 
doctrine  of  the  total  sterility  of  hybrids ;  this 
assertion  is  to  be  explained  only  by  ignorance  or 
by  a  misunderstanding  of  the  Latin  text.  Kol- 
reuter, in  fact,  does  not  speak  of  sterility,  but  of 
lessened  fruitfulness,  as  being  a  common  charac- 
teristic of  hybrids. 

The  fruitfulness  of  hybrids  is  considerably  dif- 
ferent, according  to  the  individual  genera.  For 
instance,  the  hybrids  of  Papaver,  Viola,  Verbas- 
cum,  and  Digitalis  show  but  little  fruitfulness  ; 
the  hybrids  of  Anemone,  Nicotiana,  Mentha,  Cri- 
num,  the  Cucurbitacere,  and  Passiflora  are  much 
oftener  fruitful,  while  in  Aquilegia,  Dianthus, 
Pelargonium,  Geum,  Epilobium,  Fuchsia,  Coty- 
ledon, Begonia,  Cirsium,  Erica,  Rhododendron, 
Calceolaria,  Quercus,  Salix,  Gladiolus,  Cypripe- 
dium,  Hippeastrum,  the  Gesneracese,  and  Orchids, 
the  fruitful  hybrids  are  commoner  than  the  bar- 
ren ones.  In  the  genera  Vitis,  Prunus,  Fragaria, 
and  Pyrus,  we  use  the  crosses  of  closely  related 


230  BORROWED   OPINIONS. 

species  as  fruit  plants  ;  in  Cereus,  hybrids  of  even 
widely  different  species  show  undiminished  fruit- 
fulness. 

The  sterility  of  hybrids  is  sometimes  shown  by 
their  exhibiting  no  inclination  to  blossom,  a  char- 
acteristic which  has  been  observed  particularly  in 
some  hybrids  of  Rhododendron,  Epilobium,  Ce- 
reus, and  Hymenocallis.  These  are,  however, 
rare  exceptions,  for  as  a  rule  hybrids  bloom  earlier 
and  more  profusely  than  the  pure  species  (see 
page  226). 

In  hybrids  which  have  flowers  of  only  one  sex, 
the  staminate  blossoms  often  fall  off  while  they 
are  yet  buds,  as  in  Cucurbitaceas  and  Begonias 
(hybrids  of  B.  Froebeli).  Sometimes  the  anthers 
are  arrested  in  their  growth  and  form  hermaphro- 
dite flowers,  as  has  been  observed  in  some  hybrids 
of  Pelargonium  and  Digitalis  (D.  lutea  x  pur- 
purea form  tubiflora  Lindl.).  The  common  result 
of  the  production  of  hybrids  is  a  different  forma- 
tion in  the  pollen  grains  in  the  hybrids  from  that 
of  the  parents.  Often  the  anthers  of  the  hybrids 
are  dead  and  contain  no  pollen,  or  they  are  small 
and  do  not  open  at  all.  Such  deficiency  of  pollen 
can  be  observed,  for  example,  in  Rubus  Idreus  x 
odoratus,  Ribes  aureum  x  sanguineum,  Alopecurus 
geniculatus  x  pratensis.  In  other  cases,  the  pollen 
dust  consists  of  small  powdery  grains  of  irregular 
form  and  size,  which  do  not  swell  when  moistened, 


FOCKE    ON    THE    PRIMARY   CROSS.  231 

and  among  which  are  usually  found  a  few  well- 
formed  pollen  cells  which  are  capable  of  germina- 
tion. Often  the  number  of  normal  pollen  grains 
is  greater,  and  comprises  ten  or  twenty  per  cent, 
or  more,  of  the  whole  number.  There  are  often 
found,  in  a  greater  or  less  degree,  large  angular 
grains  capable  of  swelling,  as  well  as  well-formed 
ones,  by  the  side  of  those  dwarfed  or  stunted. 
Among  crosses  of  closely  related  species,  as  Melan- 
drium  album  x  rubrum,  there  are  usually  found 
only  few  irregularities  in  the  form  of  the  pollen 
grains.  In  a  hybrid  Sinningia,  the  pollen  of  the 
second  year  of  flowering  was  better  than  that  of 
the  first. 

In  hybrids  of  undoubted  different  species,  a 
normal  formation  of  the  pollen  is  seldom  seen. 
The  statements  on  this  subject  require,  for  the 
most  part,  corroboration,  nevertheless  I  refer  to 
Nymphsea  Lotus  x  rubra,  Begonia  rubrovenia  x 
xanthina,  Isoloma  Tydseum  x  sciadocalyx,  Salix 
purpurea  x  repens  ;  almost  perfectly  formed  pollen 
grains  were  found  in  Salix  aurita  x  Caprea,  and  S. 
viminalis  x  repens. 

On  the  other  hand,  it  is  still  more  rare  that  a 
deficiency  of  pollen  is  found  in  an  evident  cross 
of  races.  Perhaps  it  could  be  found  oftener  if 
one  sought  for  it.  The  only  certain  example  of 
which  I  know  is  an  Anagallis  cross  by  myself. 
Whether  Raphanus  sativus  and  R.  Raphanistrum 


232  BORROWED    OPINIONS. 

are  to  be  considered  as  species  or  races  is  doubtful. 
Nevertheless  there  are  some  crosses  of  very  closely 
related  species  which  appear  to  be  entirely  sterile, 
as,  for  example,  Capsella  rubella  x  Bursa-pas- 
toris,  Viola  alba  x  scotophylla,  Papaver  dubium 
x  Rhoeas. 

The  sexual  capabilities  of  the  female  organs 
are,  as  a  rule,  not  so  much  weakened  in  hybrids 
as  the  male.  Nevertheless  they  are  greatly 
diminished.  Many  hybrids  never  produce  fruit. 
Even  after  many  experiments,  one  must  not  make 
definite  assertions  about  the  absolute  sterility  of 
a  hybrid  :  in  Rubus  cassius  x  Idreus,  for  example, 
one  can  see  several  thousand  blossoms  remain 
sterile,  and  nevertheless,  now  and  then,  fruit  is 
produced.  Compare,  further,  Digitalis  lutea  x 
purpurea,  Lobelia  fulgens  x  syphilitica,  Crinum  Ca- 
pense  x  scabrum.  A  morphologically  distinguish- 
able defect  of  the  ovule  of  hybrids  has  seldom  been 
referred  to  so  far,  although  it  has  been  observed  in 
Cistus,  by  Bornet.  If  one  wishes  to  obtain  a  defi- 
nite judgment  on  the  female  creative  power  in 
hybrids,  he  must  fertilize  the  ovules  with  pollen  of 
the  parent  species,  which,  as  a  rule,  develops  more 
perfect  fruit  than  the  pollen  of  hybrids  which  has 
been  weakened  in  its  generative  power.  In  some 
cases,  hybrids  whose  pollen  shows  but  slight 
potency  produce  normal  fruit  with  pollen  from 
the  parent,  as  in  Luffa. 


FOCKE    OX    THE   PRIMARY   CROSS.  233 

Some  hybrids  drop  their  entire  blossoms  un- 
wilted,  with  the  calyx  and  flower  stalk  intact, 
e.g.,  Ribes,  Nicotiana  rustica  x  paniculata,  and 
other  hybrids  of  Nicotiana. 

As  a  rule,  the  corolla  wilts,  after  a  longer 
period,  in  a  normal  manner,  or  is  thrown  off  as 
in  the  parent  species  ;  but  no  setting  of  fruit  thus 
takes  place,  or  only  a  little  of  very  poor  character. 
Sometimes  the  fruit  is  well  formed  externally, 
but  contains  no  seed.  In  many  cases  hybrids  set 
fruit,  but  to  a  less  extent  and  with  fewer  seeds 
than  the  parent  species.  Even  in  crosses  of 
closely  related  species,  the  number  of  seeds  seems 
to  be  smaller  than  in  the  parent  species ;  so,  for 
example,  according  to  Gartner,  in  Melandrium 
album  x  rubrum,  Lobelia  cardinalis  x  fulgens,  and 
even  in  undoubted  crosses  of  races  of  Verbascum. 

Hybrids  of  essentially  different  races  rarely 
show  an  undiminished  fruitfulness,  although  no 
noticeable  diminution  has  been  proved  in  Brassica 
Napus  x  oleracea,  Dianthus  Chinensis  x  pluma- 
rius,  var.  Sibiricus,  Pelargonium  pinnatum  x  hir- 
sutum,  Abutilon,  Medicago,  a  few  Cereuses  and 
Begonias,  Hieracium  aurantiacum  x  echioides,  Ni- 
cotiana alata  x  Langsdorfhi,  a  few  hybrids  of 
Erica,  Calceolaria,  Isoloma,  Veronica,  and  several 
Orchidaa.  Fruits  and  seeds  in  abundance  are  also 
found  in  many  other  garden  hybrids,  and  in  many 
wild  ones,  as  in  Roses,  Epilobiums,  Fuchsias,  Cir- 


234  BORROWED    OPINIONS. 

siums,  HieraeinmSj  Willows,  of  Lobelia  Lowii, 
etc.  In  these  cases,  however,  one  cannot  exactly 
ascertain  if  the  plants  are  primary  hybrids,  or, 
which  is  much  more  probable,  if  they  belong  to 
later  generations  or  arose  through  derivative 
hybridization  QRiickkreuzungeri) . 

In  order  to  set  seeds,  or  at  least  to  produce  a 
vigorous  progeny,  some  hybrids  require  to  be  fer- 
tilized by  other  individuals,  even  though  they  are 
themselves  hybrids ;  compare,  for  example,  hybrids 
of  Cistus,  Begonia,  Gladiolus,  and  Hippeastrum. 
In  some  hybrids,  only  the  first  flowers  produce 
seeds,  as  Aquilegia,  Dianthus,  Silene,  Lavatera 
Thuringiaca  x  Pseudolbia,  Rubus  foliosus  x  Spren- 
gelii  ;  in  other  cases,  the  first  flowers  are  regu- 
larly sterile,  while  the  later  ones  are  often  fruitful, 
as  in  Datura,  Nicotiana  rustica  x  paniculata,  N. 
rustica  x  quadrivalvis,  Mirabilis.  In  longer-lived 
plants,  often  all  the  flowers  of  the  first  years  are 
sterile,  while  later,  when  the  plant  has  reached  a 
certain  age,  a  few  fruits  are  formed  ;  this  has 
been  noticed,  for  example,  in  Rubus  Idceus  x 
csesius,  R.  Bellardii  x  csesius,  Calceolaria  integri- 
folia  x  plantaginea,  Crinum  Capense  x  scabrum. 

Although,  as  a  rule,  the  female  creative  power 
in  hybrids  is  less  weakened  than  the  male, 
still  there  are  some  cases  in  which  the  reverse 
is  true  ;  compare  Nympluea  Lotus  x  rubra,  Cico- 
nium  x  Dibrachya     in     the    genus     Pelargonium, 


FOCKE    OK   THE   PRIMARY   CROSS.  235 

Lobelia  fulgens  X  syphilitica,  Verbascum  thapsi- 
forme  x  nigrum,  Narcissus  montamis,  etc ;  tliese 
are  probably,  for  the  most  part,  only  accidental 
occurrences. 

The  longer  duration  of  the  flowers  (especially 
the  pollinized  ones)  on  mairy  sterile  hybrids,  is 
an  occurrence  which  is  analogous  to  the  longer 
duration  of  unfertilized  or  incompletely  fertilized 
flowers.  Often  in  sterile  hybrids,  especially  after 
dusting  with  the  pollen  of  the  parent  or  a  related 
species,  the  fruits  swell  more  or  less  without  per- 
fect seeds'  being  formed  in  them.  Externally 
well-formed  but  seedless  fruits  are  found  in  Cacti, 
Passifloras,  Cucurbits,  and  Orchids.  Gartner  has 
studied  this  characteristic,  which  is  of  no  special 
use  or  value  in  the  culture  of  hybrids,  very  care- 
fully ;  however,  it  offers  an  important  proof  of 
the  truth  of  the  statement  that  the  development  of 
the  outside  coats  of  the  fruits  takes  place  in  a 
normal  manner  on  account  of  the  irritation  which 
the  germinating  pollen  produces,  but  that  it  is 
nevertheless  independent  of  the  fertilization  of 
the  ovule,  and  the  development  of  the  embryo  and 
of  the  seed. 

One  can,  in  general,  make  the  statement  that 
hybrids  of  closely  related  races  are  more  fruitful 
on  the  average  than  those  of  considerably  differ- 
ent species.  One  can  also  consider,  as  a  rule,  as 
has  been  shown  above,  that  closely  related  species 


236  BORROWED    OPINIONS. 

form  hybrids  among  themselves  more  easily  than 
those  considerably  different.  Both  rules  are  true 
only  to  a  certain  extent.  If  one  should  infer  from 
these  that  hybrids  are  more  fruitful  the  easier  they 
are  formed,  then  he  would  go  far  wrong.  There 
is  no  definite  relation  between  ease  of  formation 
and  fruitf ulness  of  crosses. 

From  a  teleological  point  of  view,  we  formerly 
saw  in  the  sterility  of  hybrids  a  means  of  keeping 
"  species  "  separate.  What  purpose  this  separa- 
tion was  to  serve  was  not  explained,  unless  it  was 
for  the  convenience  of  the  systematise  Now,  on 
the  contrary,  we  ask  if  the  formation  and  sepa- 
ration of  species  does  not  really  depend  upon 
the  fruitfulness  of  the  crosses  between  the  dis- 
tinctly marked  races  of  the  parent  types.  The 
noticeable  resemblance  between  illegitimate  and 
hybrid  progeny  gives  us  no  standpoint  for  further 
investigation  of  the  cause  of  unfruitf ulness.  More 
light  may  be  given  by  the  fact  that  in  the  hybrid 
pteridophytes  and  mosses  the  formation  of  sexless 
spores  is  just  as  much  wanting  as  is  the  formation 
of  pollen  grains  in  hybrid  phanerogams.  The 
obstacle  to  the  regular  propagation  of  hybrids 
seems  to  lie  in  the  development  of  certain  cells 
which  have  the  power  to  maintain  the  type  of  the 
parent  form,  it  being  immaterial  if  these  cells  have 
sexual  functions  or  not.  In  any  case,  more  facts 
must  be  gathered  to  justify  the  adoption  or  pres- 


FOCKE   ON    THE   PROGENY   OF   CROSSES.       237 

entation  of  a  principle  of  such  scope.  This  view 
of  the  situation  can  even  now  be  considered  as  a 
hypothesis  which  certainly  as  yet  offers  no  expla- 
nation of  the  limitations  of  species,  but  it  leads 
the  way  to  a  final  solution,  because  it  brings  a 
long  list  of  different  but  plainly  analogous  phe- 
nomena as  facts  in  the  animal  and  vegetable  king- 
doms under  one  common  point  of  view. 

5.  Malformations  and  curious  forms  are  much 
more  common,  especially  in  the  flower  parts  of 
hybrids,  than  in  individuals  of  a  pure  descent. 

Compare  Papaver,  Dianthus,  Pelargonium,  Ni- 
cotiana,  Digitalis.  Double  flowers  appear  to  be 
formed  especially  easily  in  hybrids. 


II.    THE  PROGENY  OF  CROSSES. 

Hybrids  are  more  easily  and  completely  fertil- 
ized by  the  pollen  of  the  parent  forms  than  by 
their  own.  Exceptions  to  this  rule  are  hardly 
known  (although  compare  Hieracium  echioides  x 
aurantiacum),  although  no  large  number  of  ex- 
periments have  been  made  in  this  direction.  By 
their  own  pollen  is  to  be  understood  the  pol- 
len of  hybrids  of  the  same  cross,  as  well  as  that 
of  the  same  individual.  When  hybrids  grow  in 
the  vicinity  of  parent  forms,  they  must  naturally 
often  be  fertilized  by  them.  In  the  progeny  there 
will  be,  therefore,  a  number  of  forms  between  the 


238  BORROWED    OPINIONS. 

primary  hybrids  and  the  parent  species.  In  sow- 
ing the  seeds  of  hybrids,  one  cannot  always  deter- 
mine if  fertilization  from  the  parent  species  could 
have  taken  place  or  not.  The  general  statement 
that  the  progeny  of  a  hybrid  has  shown  itself  to 
be  very  variable  is  therefore  of  little  weight  or 
worth.  Sometimes  a  hybrid  is  more  easily  fertil- 
ized by  a  third  species  than  by  its  own  pollen. 
Compare,  for  example,  Nicotiana  rustica  x  panic  u- 
lata,  and  Linaria  purpurea  x  genistsefolia. 


1.    Progeny  of  Crosses  with  their  own  Pollen. 

(Ax  B)  9  x  (Ax  B)  $. 

a.  If  one  protects  the  fruitful  hybrids  from  the 
influence  of  the  parent  forms  or  other  related  spe- 
cies, then  he  obtains  hybrids  of  the  second  genera- 
tion. It  seems  to  me  that  the  progeny  of  hybrids 
appears  or  acts  very  differently  according  to  the 
length  of  their  life.  In  long-lived  plants,  the 
mingling  and  mutual  blending  of  the  two  types 
which  have  been  joined  in  the  hybrid  often  ap- 
pears to  be  more  complete,  so  that  the  progeny  also 
inherits  the  characteristic  of  the  new  intermediate 
form  or  type  in  an  equal  or  uniform  manner. 

The  progenies  of  one-  or  two-year  hybrids  are, 
as  a  rule,  very  different  and  varied  in  form ; 
compare  Pisum,  Phaseolus,  Lactuca,  Tragopogon, 


FOCKE    ON   THE   PROGENY   OF    CROSSES.       239 

Datura,  Nicotiana  alata  x  Langsdorffii,  etc.  Ex- 
ceptions are  found  in  Brassica,  CEnothera,  Nico- 
tiana rustica  x  paniculata,  Verbascum  Austriacum 
x  nigrum. 

The  progenies  of  hybrids  of  several  generations 
(mehrjahriger)  are  generally  similar,  although  the 
cases  in  which  the  intermediate  type  shows  itself 
to  be  constant  appear  to  be  much  more  frequent. 
Some  hybrids  of  Aquilegia,  Dianthus,  Lavatera, 
Geum,  Cereus,  Begonia,  Cirsium,  Hieracium,  Pri- 
mula, Linaria,  Veronica,  Lamium,  and  Hippeastrum 
appear  to  come  very  true  to  seed. 

The  progenies  of  shrubs  and  trees  are,  in  the 
majority  of  cases,  very  constant  or  invariable ; 
compare  iEsculus,  Amygdalus,  Primus,  Erica, 
Quercus,  Salix.  Also  many  hybrids  of  Fuchsia 
and  Calceolaria  are  said  to  be  constant.  The 
Rhododendron  hybrids  are  partly  true  to  seed 
and  partly  variable.  The  progeny  of  the  crosses 
of  Vitis,  Pyrus,  and  Crataegus,  on  the  other  hand, 
seem  to  be  very  variable. 

b.  The  several  forms  in  which  some  primary 
hybrids  appear  seem  to  be  unsettled  in  the  prog- 
eny. In  Dianthus,  according  to  Gartner,  the 
"exception  types,"  when  sown,  mostly  return  to 
the  normal  mongrel  form.  The  various  primary 
forms  of  the  hybrids  of  Hieracium,  Mendel  found 
to  be  true  to  seed. 

c.  C.  F.  von  Gartner  and  other  botanists  have 


240  BORROWED    OPINIONS. 

made  the  assertion  that  the  progeny  of  hybrids 
becomes,  from  generation  to  generation,  weaker 
and  less  fruitful.  It  is  certain  that  their  growth, 
which  was  at  first  increased,  gradually  decreases 
when  they  fertilize  themselves.  Gartner's  experi- 
ments, however,  were  made  on  a  very  small  scale, 
so  that  his  hybrids  were  influenced  not  only  by 
close  in-breeding,  but  also  by  the  various  circum- 
stances which  so  often  result  in  the  loss  of  garden 
plants  cultivated  only  in  small  numbers.  Even 
Gartner  noticed  exceptions,  as  in  Aquilegia,  Dian- 
thus  barbatus  x  Chinensis,  D.  Armeria  x  del- 
toides.  Crosses  of  closely  related  species  evidently 
can  be  continually  propagated  or  kept  up  with 
ease  ;  compare  Brassica,  Melandrium,  Medicago, 
Petunia.  Many  gardeners  assert  with  much  con- 
fidence that  many  hybrids  can  be  propagated  very 
well  for  several  generations  by  means  of  seeds  ; 
compare  Erica,  Lychnis,  Primula  Auricula  x  hir- 
suta,  Datura.  Many  observations  of  wild  plants 
seem  to  confirm  this  view.  The  principle  has  also 
been  laid  down  that  the  fruitfulness  of  hybrids 
increases  again  in  later  generations.  It  does  not, 
however,  appear  that  this  rule  can  have  a  very 
broad  application.  It  is  much  more  probable  that 
single  fruitful  specimens  arise  among  hybrids, 
which  can  easily  reproduce  themselves  under  favor- 
able external  conditions  by  inheriting  this  pe- 
culiar ity.      Fruitful    descendants    of   hybrids    are 


FOCKE   ON   THE   PROGENY   OF    CROSSES.       241 

probably  sometimes  the  product  of  derivative 
hybridization. 

d.  Complete  reversions  to  the  parent  forms 
without  the  aid  of  pollen  from  parent  forms  arise 
only  in  crosses  of  closely  related  races.  Even  in 
such  crosses,  true  reversions  only  seldom  take 
place,  e.g.,  Phaseolus. 

e.  From  the  variable  progeny  of  fruitful  crosses 
a  few  principal  types  often  arise  after  a  few  —  per- 
haps three  or  four  —  generations.  If  one  protects 
these  new  types  from  crossing,  they  tend  to  be- 
come constant  or  fixed.  Scientific  trials  or  exper- 
iments which  confirm  this  statement  have  been 
made  only  to  a  small  extent,  especially  by  Lecoq 
in  Mirabilis,  by  Gordon  in  Linaria  and  especially 
in  Datura.  These  gardeners  have  produced  many 
new  races  by  the  crossing  of  related  species  and 
well-fixed  races.  Also  many  wild,  fixed,  inter- 
mediate forms  may  have  arisen  in  this  manner  ; 
compare  Brassica,  Lychnis,  Zinnia,  Primula,  Petu- 
nia, Nicotiana  commutata,  Pentstemon,  Mentha, 
Lamium.  The  new  types  of  the  descendants  of 
crosses  frequently  differ  in  some  characteristic 
from  both  parent  forms.     My   Nicotiana  rustica 

x  paniculata  had  in  the  second  and  third  genera- 
tions, on  the  whole,  much  smaller  leaves  than 
either  of  the  parent  forms. 

/.  The  sterility  and  inconstancy  of  the  progeny 
of  hybrids  have  often  led  botanists  to  conclusions 


242  BORROWED    OPINIONS. 

which  are  not  confirmed  by  experience.  It  is 
entirely  wrong,  as  can  be  seen  by  the  facts  which 
have  been  stated,  to  assert  that  all  crosses  would 
necessarily  soon  be  lost  on  account  of  these  char- 
acteristics which  have  been  promiscuously  ascribed 
to  them.  The  unsettled  forms  arising  from  crosses 
are  the  plastic  material  out  of  which  not  only 
gardeners  form  their  new  varieties,  but  which 
material  is  biologically  the  more  valuable  as  it 
furnishes  new  species  in  the  household  of  nature. 


2.  Derivative  Hybridization  of  Crosses  tvith  the 
Parent  Forms. 

(i?x5J)9xiJ,(i?x5J)9x5J,l?x(ix5)J. 

As  long  as  one  laid  much  stress  upon  the  male 
or  female  influence  which  one  or  the  other  parent 
species  may  have  had  upon  the  hybrid,  a  differ- 
ence was  carefully  made  between  the  advancing 
hybrid  forms,  or  those  which  more  closely  resem- 
bled the  male  parent,  and  the  degenerating 
hybrid  forms,  or  those  which  more  closely  resem- 
bled the  female  parent.  But  these  differences 
are,  according  to  experiments  that  have  been 
made,  of  very  subordinate  importance,  or,  per- 
haps, of  none  at  all. 

By  treating  hybrids  with  parental  pollen,  one 
obtains,  as  a  rule,  a  rather  varied  progeny.     The 


FOCKE   ON   DERIVATIVE   HYBRIDS.  243 

intermediate  form  between  the  hybrid  and  respec- 
tive parent  is  apt  to  be  more  numerous  and  more 
fruitful.  Besides  this,  there  are  formed  a  less 
number  of  individuals,  some  of  which  resemble 
the  hybrid,  and  some  the  parent  species.  Both 
are  apt  to  be  but  slightly  fruitful. 

The  three-fourths  hybrids,  (A  x  B)  ?  x  A  $  , 
are  often  quite  fruitful  with  their  own  pollen  and 
appear  to  give  races  true  to  seed  easier  than  the 
original  hybrid ;  compare  iEgilops  speltaBformis. 
Gartner  observed  frequently  that  in  later  genera- 
tions the  pollen  became  more  regular  and  the 
fruitfulness  greater,  as  in  Dianthus  (Chinensis 
barbatus)  x  barbatus,  and  also  in  other  three- 
fourths  hybrids  of  Dianthus,  Lavatera,  and 
Nicotiana. 

If  one  treats  the  three-fourths  hybrid  (A  x  B)  $ 
X  A  $  again  with  pollen  from  A,  then  he 
obtains  a  seven-eighths  hybrid,  or  the  third 
hybridized  generation,  which,  as  a  rule,  is  very 
much  like  the  parent  which  furnished  the  seven- 
eighths  part,  but  it  is  still  apt  to  show  marked 
differences  in  form  and  fruitfulness  in  some  indi- 
viduals. The  last  traces  of  the  one  original 
parent  species  disappears  mostly  in  the  fourth, 
fifth,  or  even  sixth  hybridized  generation. 

Kolreuter  and  Gartner  have  completed  the 
transition  of  one  parent  species  into  the  other  in 
many   cases.     They   found   that   for   a   complete 


244  BORROWED    OPINIONS. 

change,  three  to  six  generations  were  necessary  — 
as  a  rule,  four  to  five.  Evidently  the  greater  or 
less  duration  of  the  change  depends  more  or  less 
upon  surrounding  circumstances.  Gordon  found 
that  Melandrium  album  x  rubrum  was  like  the 
parent  species  in  the  second  generation,  when 
fertilized  with  its  own  pollen,  while  Gartner 
found  three  to  four  generations  necessary  to 
bring  the  one  into  the  other  by  means  of  parental 
pollen. 

As  a  rule,  the  products  of  the  fertilization  of  a 
parent  species  with  pollen  from  a  hybrid,  as 
A  9  x(AxB)<£,  are  similar  to  those  of  the 
opposite  cross ;  nevertheless  the  statements  of 
observers  agree  that  the  variety  of  forms  is  apt 
to  be  greater  when  one  uses  the  hybrid  as  the 
male  element  ;  compare  Dianthus  and  Salix. 

There  appears,  in  the  products  of  derivative 
hybrids  of  crosses,  as  among  the  direct  progeny, 
new  characteristics,  Avhich  are  lacking  in  the 
parent  forms,  but  are  for  the  most  part  found  in 
related  races  or  species. 

3.  Hybrids  of  Several  Species. 

a.    Triple  Hybrids. 

In  the  first  years  of  his  experience,  Kolreuter 
succeeded  in  uniting  three  entirely  different  Nico- 
tiana  species  into  one  hybrid  form.     The  simplest 


FOCKE    ON   MULTIPLE   HYBRIDS.  245 

formulas  according  to  which  such  a  union  could 
take  place  are :  (A  x  B)  9  x  C  $  ,  C  9  x  ( A  x  13)  $  , 
and  (A  x  B)  9  x  (A  x  C  )  $  .  Jn  the  genera 
Dianthus,  Pelargonium,  Begonia,  Rhododendron, 
Nicotiana,  Achimenes,  Calceolaria,  Salix,  Hippeas- 
trum,  Gladiolus,  and  a  few  others,  there  has  been 
made  a  number  of  such  unions  without  any  par- 
ticular difficulty.  One  must  nevertheless  deter- 
mine if  he  unites  three  essentially  different  species, 
or  if  two  of  the  factors,  or  even  all  three  are  only 
closely  related  to  each  other.  There  are  similar 
but  evidently  different  species  which,  in  crossings 
among  themselves,  behave  almost  like  races  of  the 
same  species,  as  for  example :  — 

Melandrium  album  and  rubrum. 

Vitis  vinifera,  cordifolia,  aestivalis  and  Labrusca. 

Lobelia  fulgens,  splendens,  and  cardinalis. 

Rhododendron  Ponticum,  arboreum  and  CataAv- 
biense. 

R.  flaviim,  viscosum,  nudiflorum,  and  calendu- 
laceum. 

Berberis  Aquifolium,  and  the  most  closely 
related  species. 

Hybrids  between  the  crosses  of  two  species  of 
these  groups  with  the  third  species  of  the  same 
genus,  can  no  more  be  called  true  triple  hybrids 
than  crosses  of  species  belonging  to  some  smaller 
or  narrower  group  of  Vitis,  Lobelia,  and  Rhodo- 
dendron.     True  triple  hybrids  which  have  been 


246  BORROWED    OPINIONS. 

formed  from  three  essentially  different  species  are 
apt  to  be  much  varied  in  form,  especially  if  the 
male  parent  species  was  a  hybrid.  On  the  other 
hand,  in  those  unions  which  are  most  easily  formed 
and  are  made  by  the  formula  (A  x  B)  9  x  C  $ , 
the  type  of  C  is  apt  to  predominate  strongly, 
as,  for  instance,  Nicotiana  (rustica  x  paniculata)  ? 
X  Longsdorfhi  $ ,  Achimenes  (grandiflora  x  Can- 
dida) ?  x  longiflora  $ ,  and  other  Gesneraceas. 

The  hybrids  of  Erica  are  said  to  produce  just  as 
uniform  a  progeny  as  the  pure  species.  Several 
Salix  hybrids  have  acted  in  the  same  manner. 

For  gardeners,  therefore,  the  triple  hybrids  in 
some  genera  (as  in  Pelargonium,  Begonia,  Rhodo- 
dendron, Achimenes,  Isoloma,  Cypripedium,  Gladi- 
olus) are  very  valuable.  If  they  produce  seeds, 
their  progeny  is  very  variable. 

b.    Hybrids  of  Four  to  Six  Species. 

If  one  does  not  count  the  crossings  of  very 
nearly  related  species  (as  Vitis,  Rhododendron, 
etc.),  these  hybrids  of  four  or  more  parent  forms 
are  somewhat  rare.  We  know  them  especially  in 
the  genera  Dianthus,  Pelargonium,  Begonia,  Rho- 
dodendron, Nicotiana,  Salix,  Hippeastrum,  Gladi- 
olus. The  artificial  union  of  different  species  in 
a  single  hybrid  form  has  been  carried  farthest  by 
Wichura,  who  united  six  Salix  species. 


FOCKE    ON   CROSS-BREEDS    AND    HYBRIDS.       247 

c.    Crosses  of  Plants  Grown  Together. 

In  some  genera,  as  Pelargonium,  Fuchsia,  Be- 
gonia, Rosa,  Erica,  Rhododendron,  Achimenes,  Cal- 
ceolaria, Gladiolus,  Hippeastrum,  gardeners  have 
crossed  species  and  hybrids  in  the  most  manifold 
manner,  intentionally  and  unintentionally,  and 
have  used  the  most  promising  forms  obtained  for 
further  propagation.  The  progeny  of  this  com- 
plex crossing  is  naturally  almost  always  very  vari- 
able. There  appear,  however,  to  be  exceptions  to 
this  rule  ;  Sweet  plainly  asserts  that  one  always 
obtains  the  same  cross  from  the  crossing  of  some 
complex  Pelargonium  hybrids.  Such  constant 
complicated  hybrids  are,  according  to  him,  P. 
(hyb.)  involucratum  x  (hyb.)  ignescens  and  P. 
(hyb.)  Mostynae  x  (hyb.)  ignescens.  That  the 
Erica  and  some  Salix  hybrids  produce  a  uniform 
progeny  has  already  been  mentioned. 

III.   CROSS-BREEDS  AND  HYBRIDS. 

According  to  usage,  we  designate  unions  of  two 
different  varieties  of  one  species  as  cross-breeds, 
unions  of  two  different  species  as  hybrids.  It  is 
necessary,  on  account  of  the  indefiniteness  of  the 
term  "  variety,"  to  remember  that  only  varieties 
true  to  seed,  or  races  and  sub-species,  can  bequeath 
their  characteristics  with  any  degree  of  certainty ; 


248  BORROAVED   OPINIONS. 

inconstant  species,  which  are  so  often  designated 
as  varieties,  are  not  considered  in  the  theory  of 
hybridization. 

Many  writers  have  taken  great  pains  to  find  a 
difference  between  cross-breeds  and  hybrids  ;  they 
held  firmly  to  the  hope  that  by  means  of  trials  in 
crossing  a  boundary  between  species  and  sub- 
species could  be  formed.  Gartner,  who  expresses 
himself  plainly  in  several  parts  of  his  work  that  the 
appearance  of  crosses  clearly  proves  the  specific 
differences  of  relationships  of  the  parent  forms, 
becomes  very  reticent  as  soon  as  he  attempts,  on 
pages  574-582,  connectedly  to  unfold  the  princi- 
ples of  "variety  hybrids."  Herbert  and  Naudin 
have  formed  the  opinion,  after  their  many  experi- 
ments, that  it  is  impossible  to  draw  the  line  be- 
tween cross-breeds  and  hybrids  ;  but,  nevertheless, 
later  botanists  have  again  tried  to  find  precise  dif- 
ferences between  them. 

The  following  propositions  have  been  made  :  — 

1.  The  pollen  of  cross-breeds  is  normal :  hy- 
brids have  a  greater  or  less  number  of  imperfectly 
formed  grains  in  their  pollen. 

2.  The  fruitfulness  of  cross-breeds  is  normal : 
that  of  hybrids  plainly  diminished. 

3.  Hybrids  of  two  species  with  differently  col- 
ored blossoms  produce  flowers  of  mixed  or  uni- 
formly modified  colors :  plants  with  irregular, 
mottled  flowers  have    always  been  produced  by 


FOCKE   ON   CROSS-BREEDS    AND    HYBRIDS.       249 

the  crossing  of  varieties.  It  is  the  same  with  the 
coloring,  marking,  covering  of  the  fruits,  and 
other  characteristics. 

4.  Cross-breeds  have  a  strong  inclination  to 
return  to  the  parent  form  in  later  generations. 

These  four  propositions  are  in  the  main  correct, 
but  they  offer  little  help,  in  a  case  of  doubt,  to  a 
right  decision  as  to  specific  merits.  The  cross  of 
the  red  and  white  Anagallis  arvensis  would  have 
to  be  considered  as  a  hybrid  on  account  of  its  pol- 
len, and  as  a  cross-breed  on  account  of  the  appear- 
ance of  flowers  of  two  colors.  In  Datura,  crosses, 
which  in  other  respects  are  plainly  characterized 
as  hybrids,  easily  show  complete  returns  to  the 
parent  forms.  Hybrids  whose  fruitfulness  appears 
to  be  in  no  way  diminished  have  already  been  men- 
tioned (page  229).  One  can,  consequently,  make 
the  rule,  that  crosses  of  closely  related  races  are 
apt  to  show  the  characteristics  ascribed  to  cross- 
breeds, but  it  is  impossible  by  that  means  to  es- 
tablish any  sharp  line  between  race  crosses  and 
species  hybrids. 

Usually  a  few  other  characteristics  are  ascribed 
to  cross-breeds  by  which  they  are  distinguished 
from  the  hybrids  of  species.  Gartner  has  asserted 
that  cross-breeds  of  like  descent  are  even  in  the 
first  generation  very  dissimilar,  while  hybrids  of 
the  first  generation  are  always  very  uniform. 
This  assertion,  which  is  also  repeated  by  others, 


250  BORROWED    OPINIONS. 

is  entirely  wrong.  The  polymorphism  of  the  hy- 
brids of  the  species  of  Abntilon,  Passiflora,  Hiera- 
cium,  etc.,  has  already  been  shown,  Avhile,  on  the 
other  hand,  the  crosses  of  races,  in  the  first  gener- 
ation, are  usually  just  as  uniform  as  the  real  hy- 
brids. Again,  it  has  sometimes  been  asserted  that 
the  " varieties"  of  one  and  the  same  species,  when 
crossed  with  another  species,  always  produce  the 
same  hybrid  forms.  Gartner,  especially,  has  laid 
particular  stress  upon  this  supposed  behavior  of 
varieties,  although  he  must  have  known  that  Kol- 
reuter  had  already  observed  the  inheritance  of 
color  of  the  blossom  in  the  races  of  Mirabilis, 
Dianthus,  and  Verbascum,  the  doubling  of  flowers 
in  Aquilegia  and  Dianthus,  the  carriage  and  form 
of  the  leaf  in  the  races  of  Nicotiana  Tabacum  and 
Hibiscus.  The  white-blossoming  Datura  ferox 
gives  with  D.  Stramonium  a  white-blooming  cross, 
and  with  the  smooth-fruited  race  (var.  Bertolonii) 
of  the  same  species,  a  blue -blossoming  cross. 
Nympheoa  Lotus  x  rubra  is  different  from  N. 
Lotus  x  dentata.  It  cannot  be  in  the  least  doubt- 
ful that  the  inheritable  characteristics  of  races  and 
so-called  varieties  are  also  bequeathed  to  their 
progeny. 

One  will  hardly  go  wrong  if  he  assumes  that 
Gartner  came  to  make  this  rule  about  the  be- 
havior of  varieties  through  the  behavior  of  unfixed 
garden  crosses  and  garden  sorts.      It  is  a  matter 


FOCKE    ON   CROSS-BREEDS    AND    HYBRIDS.       251 

of  course  that  forms  which  show  themselves  un- 
fixed in  their  normal  progeny  should  produce 
polymorphous  hybrids,  and  that  unfixed  variety- 
signs  are  apt  to  disappear  entirely  in  the  products 
of  crossing  with  pure  species. 

The  true  situation  is,  in  short,  as  follows  :  — 
The  nearer  the  morphological  and  systematic  rela- 
tionship of  the  parent  forms  is,  the  less  the  sexual 
capacity  of  reproduction  in  the  cross  is  apt  to 
depart  from  the  normal  direction  ;  the  greater  the 
difference  between  the  parent  forms,  the  more,  on 
the  average,  is  the  fruitfulness  of  the  cross  weak- 
ened.    Exceptions  are  not  rare. 

The  nearer  the  parent  forms  are  related  to  each 
other,  the  oftener  the  progeny  of  crosses  show 
complete  returns  to  the  parent  forms. 

Crosses  from  nearly  related  parent  forms  some- 
times show  in  their  blossoms  and  fruits  the  pe- 
culiar characteristics  of  the  parent  forms  unmixed 
beside  each  other  ;  this  rarely  takes  place  in  crosses 
whose  parent  forms  were  considerably  different. 
Most  unsymmetrically  colored  flowers  (Mirabilis, 
Camellia,  Mimulus,  Petunia,  etc.)  first  originated 
in  the  progeny  of  crosses. 


LECTURE   V. 

pollination;  or  how  to  cross  plants. 

1.  The  Structure  of  the  Flower. 

Pollination  is  the  act  of  conveying  pollen  from 
the  anther  to  the  stigma.  It  is  the  manual  part 
of  the  crossing  of  plants.  The  word  fertilization 
is  often  used  in  a  like  sense,  although  erroneously; 
for  it  is  the  office  of  the  pollen,  not  of  the  opera- 
tor, to  fertilize  or  fecundate  that  part  of  the  flower 
which  is  to  develop  into  a  seed. 

The  chief  requirement  in  pollinating  flowers  is 
to  know  the  parts  of  the  flower  itself.     The  con- 


Fig.  1.  — Bell-tiower. 


spicuous  or  showy  part  of  the  flower  is  the  envelope, 
which  is  endlessly  modified  in  size,  form,  and  color. 

252 


STRUCTURE    OF    THE    FLOWER. 


253 


This  envelope  protects  the  inner  or  essential  organs, 
and  it  also  attracts  insects,  which  often  perform  the 
labor  of  pollination.  This  floral  envelope  is  usu- 
ally of  two  series  or  parts, — an  outer  and  commonly 
green  series  known  as  the  calyx,  and  an  inner 
and  generally  more  showy  series  known  as  the 
corolla.  These  two  se- 
ries are  well  shown  in 
the  bell-flower,  Fig.  1. 
The  calyx,  with  its  re- 
flexed  lobes,  is  at  C, 
and  the  large  bell-form 
portion  is  the  corolla. 
When  the  calyx  is  com- 
posed of  separate  parts 
or  leaves,,  each  part  is 
called  a  sepal;  in  like 
manner  each  separate 
part  of  the  corolla  is 
a  petal.  In  the  lily, 
Fig.  2,  there  is  no  dis- 
tinction between  calyx 
and  corolla  ;  or,  it  may 
be  said,  the  calyx  is  wanting.  These  envelopes 
of  the  flower  are  often  much  disguised.  This  is 
particularly  true  in  the  orchids,  one  of  which,  a 
lady-slipper,  is  illustrated  in  Fig.  3.  The  sepals 
are  seen  at  DD.  They  are  apparently  only  two, 
but  there  is  reason  to  believe  that  the  lower  sepal 


Fig.  2.  —  Flower  of  white  lily. 


254 


POLLINATION. 


is  really  made  up  of  a  union  of  two.  The  three 
inner  leaves  are  the  petals,  the  lower  one,  H, 
being  enlarged  into  the  sac  or  slipper. 

The  most  important  organs  of  the  flower,  how- 
ever, to  one  who  wishes  to  make  crosses,  are  the 
so-called  sexual  organs,  the  stamens  and  pistils. 

They  can  be  readily 
distinguished  in  the 
B  lily,  Fig.  2.  The 
six  bodies  shown  at 
S  are  the  ends  of 
the  stamens,  or  so- 
called  male  organs. 
These  stamens  gen- 
erally have  a  stalk 
or  stem,  known  as  a 
filament,  and  the  en- 
larged tip  as  the 
anther.  It  is  in  this 
anther  that  the  pol- 
len is  borne.  The 
pollen  is  generally 
made  up  of  very  mi- 
nute yellow  or  brown- 
ish grains,  although 
it  is  sometimes  in  the  form  of  a  more  or  less  glu- 
tinous or  adhesive  mass,  as  in  the  milk-weeds  and 
orchids.  The  irritating  dust  which  falls  from  the 
corn  tassels  at  the  later  cultivatings  is  the  pollen. 


Fig.  3.  —  Flower  of  greenhouse 
cypripedium. 


THE   ESSENTIAL    ORGANS.  255 

The  pistil,  or  so-called  female  organ,  is  shown  at 
OP,  Fig.  2.  The  enlarged  portion  at  O  is  the 
ovary,  which  will  develop  into  the  seed-pod.  The 
stigma,  or  the  enlarged  and  roughened  part  which 
receives  the  pollen,  is  at  P.  Between  these  two 
parts  is  the  slender  style,  a  portion  which  is  absent 
in  many  flowers. 

The  stamens  and  pistils  are  known  as  the  essen- 
tial organs  of  the  flower,  for,  whilst  the  calyx  and 
corolla  may  be  entirely  absent,  either  one  or  both 
of  these  organs  is  present ;  and  these  are  the  parts 
which  are  directly  concerned  in  the  reproduction 
of  the  species.  Like  the  floral  envelopes,  these 
essential  organs  are  often  greatly  modified,  so 
much  so  that  botanists  are  sometimes  perplexed 
to  distinguish  them  from  each  other  or  from  mod- 
ified forms  of  the  petals  or  sepals.  The  particu- 
lar features  of  these  organs  which  the  plant-breeder 
must  be  able  to  distinguish  are  the  anther  and  the 
stigma;  for  the  anther  bears  the  pollen,  and  the 
stigma  must  receive  it.  In  Fig.  1,  the  stamens 
are  shown  at  E.  In  the  flower  A,  which  has  just 
expanded,  these  stamens  are  rigid  and  in  condition 
to  shed  the  pollen,  but  in  the  flower  B,  they  have 
shed  the  pollen  and  have  collapsed.  The  stigma 
in  this  case  is  divided  into  three  parts,  but  when 
the  flower  first  opens,  these  parts  are  closed  to- 
gether, H  in  flower  A,  so  that  it  is  impossible 
that  they  receive  any  pollen  from  the  same  floAver ; 


256 


POLLINATION. 


when  the  stamens  have  withered,  however,  as  in 
B,  the  stigma,   H,  spreads  open  and  is  ready  to 


Fig.  4.  —  Flower  of  night-blooming  cereus. 

receive  any  pollen  which  may  be  brought  to  it  by 
insects  or  other  agencies.     In  this  case,  the  ovary 


THE   ESSENTIAL   ORGANS.  257 

or  young  seed-pod,  which  is  in  the  bottom  of  the 
flower,  is  not  shown  in  the  engraving. 

Some  of  the  particular  forms  of  essential  organs 
are  Avell  illustrated  in  the  accompanying  photo- 
graphs. In  the  night-blooming  cereus,  Fig.  4, 
the  many-rayed  stigma  is  shown  just  below  the 


Fig.  5.  — Flower  of  the  shrubby  hibiscus  (Hibiscus  Syriacus). 

centre  of  the  mouth  of  the  flower,  and  the  nu- 
merous stamens  are  arranged  in  a  circular  manner 
outside  of  it.  The  many  petals  and  numerous 
spreading  sepals  are  also  well  shown.  The  hibis- 
cus, Fig.  5,  has  a  central  column  with  the  anthers 
hanging  upon  it,  and  a  large  stigma  raised  beyond 


258 


POLLINATION. 


Fig.  6.  —  Bugbane  (Cimicifuga 
raceniosa). 


them.  The  wild  bugbane, 
or  cimicifuga,  is  seen  in 
Fig.  6,  natural  size.  Here 
is  a  long  spike  or  cluster 
of  flowers.  At  the  top 
are  the  unopened  buds,  in 
the  centre  the  expanded 
flowers  with  the  floral 
envelopes  fallen  away,  — 
the  fringe-like  stamens 
very  prominent,  —  and 
below  are  seen  the  pis- 
tils, the  stamens  having 
fallen.  These  pistils  will 
now  ripen  into  pods,  but 
the  tip-like  stigma  may 
still  be  seen  on  them. 
The  stamens  and  the  long 
protruding  style,  tipped 
with  its  stigma,  are  also 
shoAvn  in  the  fuchsia, 
Fig.  15.  The  essential 
organs  of  orchids  are  cu- 
riously disguised.  They 
are  combined  into  a  sin- 
gle body.  In  the  lady- 
slipper,  Fig.  3,  the  lip-like 
stigma  is  shown  at  P. 
Upon  either  side,   at   its 


STAMINATE   AND    PISTILLATE    FLOWERS.       259 

base,  is  an  anther  S.  Projecting  over  the  stigma 
is  a  greenish  ladle-like  body,  T,  which  is  a  trans- 
formed and  sterile  anther.  In  all  lady-slippers, 
these  organs  are  essentially  the  same  as  in  the 
drawing,  although  they  vary  much  in  size  and 
shape  ;  but  in  most  other  orchids,  the  two  side 
anthers,  S,  are  wholly  wanting,  and  the  terminal 
organ,  T,  is  a  pollen-bearing  anther.  In  numer- 
ous plants,  there  are  many  distinct  pistils  in  each 
flower.  Such  is  the  case  in  the  strawberry,  where 
each  little  yellow  "seed"  on  the  ripened  berry 
represents  a  pistil ;  and  the  blackberry  and  the 
raspberry,  where  each  little  grain  or  drupelet  of 
the  fruit  stands  for  the  same  organ.  A  flowering 
raspberry  is  illustrated  natural  size  in  Fig.  7,  for 
the  purpose  of  showing  the  ring  of  many  anthers 
near  the  centre  of  the  flower,  inside  of  which,  in 
the  very  centre,  is  a  little  head  of  pistils. 

It  frequently  occurs  that  the  stamens  and  pistils 
are  borne  in  different  flowers,  rather  than  together 
in  the  same  flower  as  they  are  in  the  examples 
which  we  have  studied.  In  these  cases  the  flower 
is  said  to  be  staminate,  or  male  or  sterile,  in  one 
case,  and  pistillate,  female  or  fertile,  in  the  other 
case.  If  these  two  kinds  of  flowers  are  borne 
together  upon  the  same  plant,  as  in  pumpkins, 
melons,  cucumbers,  chestnuts,  oaks,  and  begonias, 
the  plant  is  said  to  be  monoecious;  but  if  the  stami- 
nate and  pistillate  flowers  are  on  entirely  different 


260  POLLINATION. 

plants,  as  in  willows  and  poplars,  the  plant  is  dioe- 
cious. The  two  kinds  of  squash  flowers  are 
shown  in  Fig.  8.  The  pistillate  flower  is  on 
the  left,  and  it  is  at  once  distinguished  by  the 
ovary  or  little  squash  beloAV  the  colored  portion, 


Fig.  7.  —  Blossom  of  flowering  raspberry  (Hub us  odoratus). 

or  corolla  of  the  flower.  The  lobed  stigma  is 
seen  in  the  centre.  The  staminate  flower  is  on 
the  right.  It  has  a  longer  stem,  no  ovary,  and  the 
anthers  are  united  into  a  conspicuous  cone  in  the 
centre.  The  flowers  expand  early  in  the  morning. 
Insects  carry  pollen  to  the  pistillate  flower,  which 


STAMLNATE   AND    PISTILLATE   FLOWERS.       261 

then  begins  to  set  its  fruit,  whilst  the  staminate 
flower  dies.  The  flowers  of  the  common  wild 
clematis  are  shown  in  Fig.   9.      Upon  the  right 


Fig.  8.  —  Squash  flowers  of  each  sex. 

are  the  sterile  flowers,  which  are  wholly  stami- 
nate. On  the  left,  the  flowers  with  larger  sepals 
—  the  petals  are  absent  —  have  a  cone  of  pistils  in 


262 


POLLINATION. 


the  centre,  and  a  few  short  and  sterile  stamens 
spreading  from  the  base  of  the  cone.  These  dif- 
ferent flowers  are  borne  on  different  plants  in  this 
species  of  clematis,  and  the  plants  are  therefore 
practically  dioecious,  because  the  stamens  of  the 
pistillate  flowers  generally  bear  no  pollen.  A  sim- 
ilar mixed  arrangement  occurs  in  some  strawber- 


efe 

.■*■-■ .« 

*SrSi- 

Fig.  9.  —  Flowers  of  clematis  (Clematis  Virginiana). 


ries,  except  that  there  are  no  purely  staminate 
flowers.  There  are  purely  pistillate  varieties, 
others,  like  the  Crescent,  with  a  few  nearly  or 
quite  abortive  stamens  at  the  base'_  of  the  cone  of 
pistils,  and  others  in  which  the  flowers  are  per- 
fect or  hermaphrodite,  that  is,  containing  the  two 
sexes. 


COMPOSITOUS   FLOWERS.  263 

The  compositous  flowers  —  like  the  asters,  daisies, 
goldenrods,  sunflowers,  dahlias,  zinnias,  chrysan- 
themums, and  their  kin  —  need  to  be  considered 
in  still  a  different  category.  In  these  plants,  the 
head,  or  so-called  flower,  is  an  aggregation  of  sev- 
eral or  many  small  flowers  or  florets.  Each  seed 
in  a  sunflower  head,  for  example,  represents  a  dis- 
tinct flower.  Sometimes  all  of  these  flowers  are 
perfect,  —  contain  the  two  sexes,  —  and  sometimes 
they  are  pistillate  or  staminate  in  different  parts 
of  the  head ;  and  in  some  cases  the  plants  are 
dioecious.  In  many  plants  of  the  composite  fam- 
ily, the  flowers  near  the  border  of  the  head  are 
unlike  those  of  the  centre  or  disc,  in  having  a 
long  ray-like  corolla ;  and  these  ray-flowers  are 
frequently  of  different  form  from  the  others  in  the 
character  of  the  essential  organs.  Very  frequently 
the  ray-flowers  are  pistillate,  whilst  the  disc-flow- 
ers are  generally  hermaphrodite.  The  anthers,  in 
these  plants,  are  united  in  a  ring  closely  about  the 
style  and  below  the  stigma. 

The  ovary,  as  we  have  seen,  ripens  into  the 
pod,  berry,  or  other  fruit ;  but  it  is  not  able  to 
bear  seeds  until  it  is  assisted  by  the  pollen.  The 
pollen  falls  upon  the  roughish  or  sticky  surface 
of  the  stigma,  and  there  germinates  or  sends  a 
minute  tube  downwards  through  the  style  and 
finally  reaches  the  ovule,  which,  when  fertilized, 
rapidly  ripens  into  the  seed.     The  nature  of  this 


264  POLLINATION. 

fecundation  is  not  germane  to  the  present  subject ; 
but  it  may  be  said  that  only  one  pollen  grain  is 
necessary  to  the  fertilization  of  a  single  ovule,  but 
the  addition  of  a  superabundance  of  pollen  greatly 
stimulates  the  growth  of  the  fleshy  or  enveloping 
parts  of  the  fruit.  It  is  important  that  the  person 
who  desires  to  cross  plants  should  become  familar 
with  the  stigma  when  it  is  "ripe,"  receptive,  or 
ready  to  receive  the  pollen.  This  condition  is  gen- 
erally indicated  by  the  glutinous  or  sticky  or  moist 
condition  ol  the  stigma,  or  in  those  stigmas  which 
are  not  glutinous  it  is  told  by  the  appearing  of  a 
distinctly  roughened  or  papillose  condition.  This 
receptive  condition  generally  occurs  about  as  soon 
as  the  flower  opens.  If  pollen  is  withheld,  the 
stigma  will  remain  receptive  much  longer  than 
when  fertilization  has  taken  place,  —  in  some  flow- 
ers for  two  or  three  days. 

The  pollen  is  discharged  from  the  anther  in 
various  ways,  but  it  most  commonly  escapes 
through  a  chink  or  crack  in  the  side  of  the 
anther.  Sometimes  it  escapes  through  pores  at 
one  end  of  the  anther ;  and  in  other  cases  there 
are  more  elaborate  mechanisms  to  admit  of  its  dis- 
charge. In  most  plants,  the  anthers  and  stigma 
in  the  same  flower  mature  at  different  times,  so 
that  close-fertilization  or  in-breeding  is  avoided. 
This  is  well  illustrated  in  the  bell-flower,  Fig.  1. 
Here  the  anthers  wither  and  die  before  the  stig- 


PREPARING   THE   FLOWERS.  265 

matic  lobes  open.  In  other  cases,  the  stigma 
matures  first,  although  this  is  not  the  usual  con- 
dition. 

II.   Manipulating  the  Flowers. 

We  are  now  familiar  with  the  essential  principles 
in  the  pollination  of  flowers.  Before  a  person  pro- 
ceeds to  operate  upon  a  flower  with  which  he  is 
unfamiliar,  he  should  carefully  study  its  structure, 
so  as  to  be  able  to  locate  the  different  organs,  and 
to  discover  when  the  pollen  and  the  stigma  are 
ready  for  the  work. 

The  first  and  last  rule  in  the  pollinating  of  plants 
is  this  :  Exercise  every  precaution  to  prevent  any 
other  pollination  than  that  which  you  design  to  give. 
The  anthers,  therefore,  must  be  removed  from  the 
flower  before  it  opens.  This  removal  of  the  anthers 
is  known  as  emasculation.  Just  as  soon  as  this 
is  done,  tie  up  the  flower  securely  in  a  bag  to 
protect  it  from  foreign  pollen  which  may  be 
brought  by  wind  or  insects.  As  soon  as  the 
stigma  is  ripe,  remove  the  bag  and  apply  the  de- 
sired pollen,  placing  the  bag  on  the  flower  again, 
where  it  must  remain  until  the  seeds  begin  to 
form.  The  stigma  may  be  receptive  the  day  fol- 
lowing emasculation,  or,  perhaps,  not  until  a  week 
afterwards.  Much  depends  upon  the  age  of  the 
bud  when  emasculation  takes  place.      It  is  gener- 


266  POLLINATION. 

ally  best  to  delay  emasculation  as  long  as  possible 
and  not  have  the  flower  oj^en  ;  but  the  operator 
must  be  sure  that  the  anthers  do  not  discharge  or 
that  insects  do  not  get  into  the  flower  before  he 
has  emasculated  it.     The  bud  at  B,  in  Fig.  3,  is 


Fig.  10.  —  Tobacco  flowers,  showing  the  parts  of  the  flower,  a  hud 
ready  to  be  emasculated,  and  an  emasculated  subject. 

nearly  ready  to  emasculate.  The  older  buds  on 
the  top  of  the  spike  of  bugbane,  Fig.  6,  are  ready 
to  operate  upon ;  and  so  is  the  bud  seen  at  the 
left  in  Fig.  7. 

The  manner  of  emasculating  the  flower  varies 


EMASCULATING.  267 

with  the  operator.  It  is  a  common  practice  to 
clip  off  the  anthers  with  a  pair  of  small  scissors, 
or  to  hook  them  out  with  a  bent  pin  or  a  crochet 
hook.  Others  nse  tweezers.  For  myself,  how- 
ever, I  do  not  like  any  of  these  methods,  because 
the  anthers  are  apt  to  drop  into  the  bottom  of  the 
corolla,  where  it  is  sometimes  difficult  to  rescue 
them ;  and  if  one  uses  tweezers,  there  is  always 
danger  that  the  anthers  may  be  crushed  and  that 
some  of  the  pollen  may  adhere  to  the  instrument 
and  contaminate  future  crosses.  I  therefore  usu- 
ally cut  the  corolla  completely  off  just  above  the 
ovary,  with  a  pair  of  small,  long-handled  surgeon's 
scissors  (see  Fig.  12),  removing  everything  but 
the  pistil.  The  operation  is  explained  in  Fig.  10, 
which  shows  the  tobacco  flower.  The  flower  at 
the  left  shows  the  pin-head  stigma  in  the  centre  of 
the  throat,  and  the  five  anthers  surrounding  it. 
The  second  flower  is  spread  open  for  the  purpose 
of  showing  these  organs.  The  third  figure  is  a 
bud  in  the  right  condition  for  operation.  The 
right-hand  figure  shows  this  bud  cut  around  with 
the  points  of  the  scissors,  leaving  only  the  pistil. 
The  line  at  W,  in  Fig.  2,  shows  where  the  flower 
of  the  lily  might  be  cut  off.  The  manner  of  oper- 
ating upon  a  compositous  flower  is  shown  in  the 
picture  of  the  zinnia,  Fig.  11.  In  this  plant  the 
outer  florets  of  the  head  are  pistillate,  whilst  those 
of   the    disc    are   perfect.     It   is    only    necessary, 


268  POLLINATION. 

therefore,  to  remove  the  central  stamen-bearing 
flowers  before  any  of  them  open,  and  to  cover  the 
flower  up  before  any  of  the  pistils  near  the  border 


Fig.  11.  —  Zinnia  flowers;  the  upper  head  ready  for  emasculation. 

the  lower  one  showing  the  operation  performed. 

have  protruded  themselves.  The  upper  head  in 
Fig.  11  shows  the  untreated  sample,  whilst  the 
lower  one  shows  the  same  with  the  cone  of  central 


EMASCULATING.  269 

flowers  pulled  out.  This  treated  head  should  now 
be  covered,  to  await  the  maturing  of  the  stigmas. 
In  many  compositous  plants,  however,  the  case  is 
not  so  simple  as  this,  because  all  the  flowers  are 
perfect.  In  such  cases,  nearly  all  the  florets  should 
be  removed  from  the  head,  and  a  few  remaining 
ones  emasculated  in  essentially  the  same  manner 
as  described  for  the  tobacco,  Fig.  10.  Whenever 
flowers  are  borne  in  clusters,  nearly  all  of  them 
should  be  removed  and  the  attention  confined  to 
only  two  or  three  of  them.  One  is  then  more  cer- 
tain of  getting  seeds  to  set.  In  some  cases,  like 
the  apple  cluster,  only  one  or  two  flowers  of  any 
cluster  ever  set  fruit,  and  the  operator  should  then 
choose  the  two  or  three  strongest  and  most  prom- 
ising buds,  and  cut  all  the  others  off. 

Flowers  which  bear  no  stamens,  as  the  pistillate 
flowers  of  squashes,  strawberries,  and  many  other 
plants,  of  course  do  not  require  emasculating. 
They  should  be  tied  up  while  in  bud,  however,  to 
prevent  the  access  of  any  foreign  pollen.  Indian 
corn  is  a  case  in  point.  The  pistillate  flowers  are 
on  the  ear,  each  kernel  of  corn  representing  a  single 
floAver.  The  silks  are  the  stigmas.  If  it  is  desired 
to  cross  corn,  therefore,  the  ear  should  be  covered 
before  any  silks  are  protruded,  and  the  pollen  should 
be  applied  some  days  later,  when  the  silks  are  full 
grown.  The  staminate  or  male  flowers  are  in  the 
tassel. 


270  POLLINATION. 

The   pollen   should   be  derived  from  a  flower 
which  has  also  been  protected  from  wind  and  in- 


Fig.  12.  —  Instruments  used  in  pollinating  flowers,  natural  size. 
Pin  scalpel,  scissors,  lens. 


APPLYING    THE   POLLEN.  271 

sects,  because  foreign  pollen  may  have  been 
dropped  upon  an  anther  by  an  insect  visitor  and  it 
may  be  unknowingly  transferred  by  the  operator. 
The  pollen-bearing  parent  needs  no  operation,  of 
course,  but  the  flower  should  have  been  tied  up 
in  a  bag  when  it  was  in  bud.  The  pollen  is  best 
obtained  by  picking  off  a  ripe  anther  and  crush- 
ing it  upon  the  thumb-nail.  Then  it  is  trans- 
ferred to  the  stigma  by  a  tiny  scalpel  made  by 
hammering  out  the  small  end  of  a  pin,  as  shown, 
full  size,  at  the  left  in  Fig.  12.  The  stigma 
should  be  entirely  covered  with  the  pollen,  if  pos- 
sible.    It  is  often  advised  to  use  a  camel's  hair 


Fig.  13.  —  Ladle  for  pollinating  house  tomatoes. 

brush  to  transfer  the  pollen,  but  much  of  the 
pollen  sticks  amongst  the  hairs  of  the  brush  and 
is  ready  to  contaminate  a  future  cross  ;  and  where 
the  pollen  is  scarce  it  cannot  be  conserved  to 
advantage  by  a  brush.  In  some  cases  the  pollen 
is  discharged  so  freely  that  the  anther  may  be 
rubbed  upon  the  stigma,  or  even  shaken  over  it, 
but  in  most  instances  it  will  be  necessary  to  actu- 
ally place  the  pollen  upon  the  stigma  with  some 
hard  instrument.  When  pollinating  house-grown 
melons  and  cucumbers,  the  staminate  flower  is 
broken  off,   the    corolla   stripped   back,   and   the 


272 


POLLINATION. 


anther-cone  inserted  into  the  pistillate  flower, 
where  it  is  allowed  to  remain  until  it  dries  and 
falls  away.  In  pollinating  house  tomatoes,  an 
implement  shown  in  Fig.  13,  one-third  size,  is 
used.  This  is  simply  a  watch-glass,  T,  secured 
to  a  handle.  When  the  house 
is  dry,  at  midday,  the  watch- 
glass  is  held  under  the  flowers, 
which  are  tapped,  and  the  pol- 
len falls  into  the  glass.  The 
glass  is  then  held  up  under 
another  flower  until  the  stigma 
rests  in  the  pollen.  It  should 
be  said,  however,  that  this  pol- 
lination of  tomatoes  is  for  the 
purpose  of  making  the  fruit 
set  in  the  absence  of  insects, 
,  not  to  effect  a  cross.  If  the 
c.^J^,^__^!Sj  latter  purpose  were  the  object 
sought,   the  flowers   which  are 

Fig.  14. -Bag  for  cov-  t      fe  ^  d  ^    need 

enng  the  flowers. 

to  be  emasculated. 
Sometimes  it  is  impossible  to  secure  the  pollen 
at  the  time  the  stigma  is  ready.  In  some  cases 
of  this  kind,  the  intended  parents  can  be  grown 
under  glass  so  as  to  bring  them  into  bloom  at  the 
same  time.  In  other  cases,  it  is  necessary  to  keep 
the  pollen  for  some  time.  The  length  of  time 
that  pollen  will  keep  varies  with  the  species  and 


KEEPING   THE   POLLEN. 


273 


probably  also  with  the  strength  and  vigor  of  the 
plant  which  bears  it.  As  a  rule,  it  Avill  not  keep 
more  than  a  week  or  two,  and,  in  general,  it  may 


Fig.  15.  —  Fuchsias,  showing  the  stamens  and  pistils,  and  a  bud 
ready  to  be  emasculated. 

be  said  that  the  fresher  it  is  the  better  it  may  be 
expected  to  act,      It  is  best  kept  in  dry  and  tig] it 


274 


POLLINATION. 


paper  bags,   such   as    are    used   for  covering   the 
flowers. 

Something  more  should  be  said  about  the  bags 
which  are  used  for  covering  the  flowers.  After 
having  tried  every  kind  which  is  recommended, 
I  find  grocer's  manilla  bags  much  the  most  satis- 
factory. For  most  flowers  the  four-ounce  size  is 
the    handiest.     When  the  bags    are   still  flat,   as 


Fig.  16 


Fuchsia  flower  emasculated. 


they  come  from  the  packages,  a  hole  is  made 
through  the  two  overlapping  folds  near  the  open- 
ing, and  a  string  is  passed  through  it  and  then 
tied  at  one  of  the  folds,  as  shown  in  Fig.  14. 
The  bag  is  then  ready  for  use.  Before  it  is  put 
on  the  flower,  the  lower  end  of  it  is  dipped  in 
water  to  soften  it  so  that  it  can  be  puckered 
tightly  about  the  stem  and  thereby  prevent  the 


BAGGING    THE   FLOWER. 


275 


entrance  of  any  in- 
sect. A  bag  is  put 
upon  the  seed-bear- 
ing flower  when 
emasculation  is  per- 
formed, and  upon 
the  intended  pol- 
len parent  when 
the  flower  is  still 
in  bud.  The  bag 
may  be  removed 
from  the  emascu- 
lated flower  from 
time  to  time  to  ex- 
amine the  stigma, 
and  •  again  when 
the  pollen  is  ap- 
plied ;  but  it  should 
not  be  taken  off 
permanently  until 
the  pod  or  fruit 
begins  to  grow. 

By   way   of   re- 
capitulation, let  us 
consider  the  cross- 
ing    of     a    fuchsia    Fig.  17.  —  Fuchsia  flower  tied  up  after 
flower.     In  Fig.  15  emasculation, 

two  flowers  are  shown  in  full  bloom,  with  the  long 
style  and  the  eight  shorter  stamens.     The  single 


276  POLLINATION. 

bud  is  just  the  right  age  to  emasculate.  We 
therefore  cut  off  the  two  flowers  and  emasculate 
the  bud,  as  in  Fig.  16.  The  pollen  of  another 
flower  is  applied  and  the  bag  is  tied  on,  as  seen  in 
Fig.  17.  The  best  label  is  a  small  merchandise 
tag,  and  this  records  the  staminate  parent  and 
the  date. 

It  will  be  seen  that  in  the  operation  of  emascu- 
lating the  fuchsia  flower  we  cut  off  the  sepals  as 


Fig.  18.  —  Tomato  and  quince,  showing  how  the  sepals  were  cut  off 
in  emasculating. 

well  as  the  petals.  In  some  plants  the  calyx 
adheres  to  the  full-grown  fruit,  as  on  the  apple, 
pear,  quince,  gooseberry,  or  persists  at  the  base 
of  the  fruit,  as  in  the  tomato,  pea,  raspberry.  In 
these  fruits,  therefore,  the  cutting  awa}r  of  the 
calyx  leaves  an  indelible  mark  which  at  once  dis- 
tinguishes  the    fruits  which   have   been   crossed, 


CROSSING    IX    FLOW  EH  LESS    PLANTS. 


277 


even  if  the  labels  are  lost.      In  Fig.  18  a  tomato 
and  quince  are  shown  which  are  thus  marked. 

All  the  foregoing  remarks  do  not  apply  to  the 
crossing  of  ferns,  lycopods,  and  the  like,  because 
these  plants  have  no  flowers;  yet  cross-fertiliza- 
tion may  take  place  in  them.      When  the  spores 


si 


Fig.  19.  — Pollinating  kit. 


of  these  flowerless  plants  are  sown,  a  thin  green 
tissue,  or  prothallus,  appears  and  spreads  over  the 
ground.  In  this  tissue  the  separate  sex-organs 
appear,  and  after  fecundation  takes  [dace,  the 
fern,  as  we  commonly  understand  it,  springs  forth. 
Thereafter,  this   fern    lives    an    asexual    life    and 


278 


POLLINATION. 


produces  spores  year  after  year ;  but  it  is  only  in 
this  primitive  prothallic  stage  that  fertilization 
takes  place,  once  in  the  lifetime  of  the  plant.  If 
these  plants  are  to  be  crossed,  the  only  procedure 
open  to  the  gardener  is  to  sow  the  spores  of  the 
intended  parents  together  in  the  hope  that  a  nat 
ural  mixing  may  take  place.  There  are  various 
well-authenticated  fern  hybrids. 

The  pollination  of  flowers  is  such  a  simple  Avork 
that  few  implements  are  required  for  its  easy 
performance.      Great  care  is  more  important  than 


Fig.  20.— Pollinating  kit. 


any  number  of  tools.  Every  one  who  expects  to 
cross  plants  should  provide  himself  with  the  three 
instruments  shown  in  Fig.  12,  —  a  pin  scalpel, 
sharp-pointed  scissors,  and  a  large  hand-lens.  If 
one  contemplates  much  experimenting  in  this 
direction,  however,  it  is  economy  of  time  to  have 
some  sort  of  a  box  in  which  there  are  compart- 
ments for  the  various  necessities.  These  various 
compartments  suggest  at  once  whatever  accesso- 
ries are  wanting,  and  they  hold  a  sufficient  supply 


IMPLEMENTS    USED   IN   CROSSING.  279 

for  several  hundred  operations.  There  should 
be  a  compartment  for  bags,  string,  lens,  scissors, 
and  pencils,  tags,  note-book,  and  the  like.  Figs. 
19  and  20  show  a  convenient  case  for  an  experi- 
menter, and  one  which  I  have  used  with  satisfac- 
tion for  several  years.  This  kit  is  twelve  inches 
long,  nine  inches  wide,  and  three  inches  deep. 

The  chances  of  success  in  pollinating  are  dis- 
cussed in  Lecture  II.  (page  88). 


GLOSSARY. 

1.    The  Flower. 

Anther.  —  That  portion  of  the  stamen  which  bears  the 
pollen.     It  is  the  uppermost  portion  of  the  stamen. 

<  'alyx.  —  The  outer  series  of  floral  envelopes,  usually 
green.  The  various  separate  parts  of  the  calyx  are 
sepals. 

Corolla.  —  The  inner  series  of  floral  envelopes,  usually 
colored  and  forming  the  showy  part  of  the  flower.  If 
it  is  divided  into  separate  parts,  these  are  called  petals. 

Essential  organs.  —  The  stamens  and  pistils. 

Female.  —  Said  of  flowers  which  have  only  pistils  or  the 
seed-bearing  part,  or  of  plants  which  bear  only  such 
flowers ;  applied  also  to  the  pistils  in  any  flower. 

Filament.  —  The  stalk  or  stem  of  a  stamen,  bearing  the 
anther. 

Floral  envelopes. — The  calyx  and  corolla. 

Male.  —  Said  of  flowers  which  bear  only  stamens,  or  of 
plants  which  have  only  staminate  flowers ;  also  applied 
to  the  stamens  or  pollen-bearing  organs  of  flowers. 

Ovary.  —  The  lowest  part  of  the  pistil,  containing  the 
ovules.  It  is  the  most  thickened  portion  of  the  pistil, 
and  it  may  stand  either  below  or  above  the  petals. 
The  ovary  ripens  into  the  fruit. 

Ovule.  —  A  body  in  the  ovary  which  ripens  into  a  seed. 

Pet'-al.  —  The  separate  portions  or  leaves  of  the  corolla. 

Pistil.  —  The  seed-bearing  organ  of  the  flower.  It  always 
comprises  two  parts,  the  ovary  —  which  becomes  the 
pod  or  fruit  —  and  the  stigma.  Usually  there  is  a 
281 


282  GLOSSARY. 

style  connecting  the  two.     Often  called  the  fertile  or 
female  organ. 

Pistillate.  —  Said  of  a  plant  or  flower  which  has  only  pis- 
tils or  female  organs. 

Pollen.  —  The  contents  of  the  anther,  capable  of  fertil- 
izing the  ovules.  It  is  usually  composed  of  minute 
yellow  or  brown  grains. 

Se'-pal.  —  The  separate  portions  or  leaves  of  the  calyx. 

Spore.  —  The  reproductive  organ  of  flowerless  plants,  by 
means  of  which  they  propagate,  as  other  plants  propa- 
gate by  means  of  the  seed.     The  spore  is  asexual. 

Stamen.  —  The  pollen-bearing  organ  of  the  flow7er.  Often 
called  the  male  or  sterile  organ.  Its  essential  part  is 
the  anther.  The  stalk,  when  present,  is  called  the 
filament. 

Staminate.  —  Said  of  a  flower  or  plant  which  bears  only 
stamens  or  male  organs. 

Stigma. —  The  top  end  of  the  pistil,  where  the  pollen 
lodges  and  germinates.  It  is  usually  a  somewhat  ex- 
panded surface,  and  is  roughened,  or  sticky,  or  moist 
when  ready  to  receive  the  pollen. 

Style. — The  more  or  less  slender  portion  of   the  pistil 
which  lies  between  the  stigma  and  ovary.     The  pol- 
len-tubes pass  through  it  in  reaching  the  ovary. 
2.    Crossing. 

Bigener;  bigeneric-liybrid.  —  A  hybrid  between  species  of 
different  genera. 

Bigeneric  half-breed.  —  The  product  of  a  cross  between 
varieties  of  species  of  different  genera. 

Close-fertilization  ;  self-fertilization.  —  The  action  of  pollen 
upon  the  pistil  of  the  same  flower. 

Close-pollination  :  self-pollination.  —  The  transfer  of  pollen 
to  a  pistil  of  the  same  flower. 

Cross.  —  The  offspring  of  any  two  flowers  which  have 
been  cross-fertilized. 


GLOSSARY.  283 

Cross-breed;  half-breed;  mongrel;  variety-hybrid.  —  A  cross 
between  varieties  of  the  same  species. 

Cross-fertilization.  —  The  action  of  pollen  upon  the  pistil 
of  another  flower  of  the  same  species. 

Crossing.  —  The  operation  or  practice  of  cross-pollinating. 

( 'ross-pollination.  —  The  conveyance  of  pollen  to  the 
stigma  of  another  flower. 

Derivative-  or  derivation-hybrid;  secondary-hybrid.  —  A  hy- 
brid between  hybrids,  or  between  a  hybrid  and  one  of 
its  parents. 

Fertilization ;  fecundation ;  impregnation.  —  The  action  of 
the  pollen  upon  the  ovules. 

Half-hybrid.  —  The  product  of  across  between  a  species 
and  a  variety  of  another  species. 

Hybrid.  —  The  offspring  of  crossed  plants  of  different 
species. 

Hybridist)) ;  hybridity.  —  The  state,  quality,  or  condition 
of  being  a  hybrid. 

Hybridization.  —  The  state  or  condition  of  being  hybrid- 
ized, or  the  process  or  act  of  hybridizing. 

Hybridizing.  —  The  operation  or  practice  of  crossing  be- 
tween species. 

Individual  cross.  —  The  offspring  of  two  crossed  flowers 
on  the  same  plant. 

Individual  fertilization.  —  Fertilization  between  flowers 
upon  the  same  plant. 

Mongrel.  —  A  cross. 

Mule.  —  A  sterile  (seedless)  hybrid. 

Pollination.  —  The  conveyance  of  pollen  from  the  anther 
to  the  stigma  (page  252). 

The  term  cross  is  used  to  denote  the  offspring  of  any 
sexual  union  between  plants,  whether  of  different 
species  or  varieties,  or  even  different  flowers  upon  the 
same  plant.     It  is  a  general  term.     And  the  word  is 


284  GLOSSARY. 

also  sometimes  used  to  denote  the  operation  of  per- 
forming- or  bringing  about  the  sexual  union.  There 
are  different  kinds  of  crosses.  One  of  these  is  the 
hybrid.  A  hybrid  is  a  cross  between  two  species,  as  a 
plum  and  a  peach,  or  a  raspberry  and  a  blackberry. 
There  has  lately  been  some  objection  urged  against 
this  term,  because  it  is  often  impossible  to  define  the 
limitations  of  species,  —  to  tell  where  one  species  ends 
and  another  begins.  And  it  is  a  fact  that  this  diffi- 
culty exists,  for  plants  which  some  botanists  regard  as 
mere  varieties  others  regard  as  distinct  species.  But 
the  term  hybrid  is  no  more  inaccurate  than  the  term 
species,  upon  which  it  rests;  and,  so  long  as  men  talk 
about  species,  so  long  have  we  an  equal  right  to  talk 
about  hybrids.  Here,  as  everywhere,  terms  are  mere 
conveniences,  and  they  seldom  express  the  whole  truth. 
In  common  speech  the  word  hybrid  is  much  misused. 
Crosses  between  varieties  of  one  species  are  termed 
half-breeds  or  cross-breeds,  and  those  between  different 
flowers  upon  the  same  plant  are  called  individual 
crosses. 
3.   Classification. 

Break.  —  A  radical  departure  from  the  type.  Ordinarily 
used  in  the  sense  of  sport,  but  in  its  larger  meaning  it 
refers  to  the  permanent  appearance  of  apparently  new 
or  very  pronounced  characters  in  a  species. 

Bud-variation.  —  Variation  or  departure  from  a  type 
through  the  agency  of  buds  (pages  28,  153). 

Bud-variety.  —  A  variety  resulting  from  bud-variation. 
Bud-sport. 

Family  (Order  in  botany.)  —  A  group  of  genera  and 
species;  as  Cupuliferm,  the  Oak  Family,  Rosacea?,  the 
Rose  Family. 

Worm. —  A  minor  variety,  usually  transient,  produced  by 
some  local  environment, 


GLOSSARY.  285 

Genus  (plural,  genera). —  A  group  or  kind  comprising  a 
greater  or  less  number  of  closely  related  species;  as 
Acer,  the  maples,  Fragaria,  the  strawberries. 

Race.  —  A  fixed  cultural  variety;  that  is,  a  cultural  va- 
riety which  reproduces  itself  more  or  less  uniformly 
from  seeds. 

Seedling.  —  A  plant  growing  directly  from  seed,  without 
the  intervention  of  grafts,  layers,  or  cuttings. 

Seed-variation.  —  Variation  or  departure  from  a  type 
through  the  agency  of  seeds. 

Seed-variety.  —  A  variety  resulting  from  seed- variation. 

Species  (plural,  species).  —  An  indefinite  term  applied  to 
all  individuals  of  a  certain  kind  which  come  or  are 
supposed  to  come  from  a  common  parentage.  A  per- 
ennial succession  of  normal  or  natural  similar  indi- 
viduals perpetuated  by  means  of  seedage.  "All  the 
descendants  from  the  same  stock." —  Gray. 

Sport.  —  A  variety  or  variation  which  appears  suddenly 
and  unaccountably,  either  from  seeds  or  buds;  more 
properly  restricted  to  varieties  originating  from  buds, 
and  so  used  in  this  book. 

Stock.  —  The  parentage  of  a  particular  strain  or  variety. 

Strain.  —  A  sub-variety,  or  individuals  of  a  variety,  which 
has  been  improved  and  bred  under  known  conditions. 

Variation.  —  1.  The  act  or  condition  of  varying  or  be- 
coming modified.  2.  A  transient  variety,  more  or  less 
incapable  of  being  fixed  or  rendered  permanent. 

Variety.  —  A  form  or  series  of  forms  of  a  species  marked 
by  characters  of  less  permanence  or  less  importance 
than  are  the  species  themselves. 

Wilding.  —  A  wild  individual  from  a  cultivated  species. 


INDEX 


Abortive  varieties,  152. 
Abutilon,  crosses,  220,  233,  250. 
Accident,  154. 
Acclimatization,  24,  20. 
Acer,  bud-variety,  177. 
Achimenes,  crosses,  245,  246,  247. 
Acorns,  bud-variety,  177. 
Acquired  characters,  14. 
Adult  forms,  156. 
^Egilops,  crosses,  243. 
./Esculus,  bud-variety,  178. 
^Esculus,  crosses,  239. 
Agatlnea,  bud-variety,  178. 
Ageratum,  bud-varieties,  17S. 
Agrostemma  Coeli-rosa,  dwarfs,  144. 
Albinos,  148. 
Allut,  Cazalis,  211. 
Almond,  bud-variety,  179. 
Alnus,  crosses,  226. 
Alopecurus,  crosses,  230. 
Altitude  and  plants,  25. 
Amelioration,  gradual,  50. 
Amygdalus,  crosses,  239. 
Anagallis,  crosses,  222,  223,  231. 
Anemone,  crosses,  224,  229. 
Anemone,  varieties,  179. 
Animal  and  plant  contrasted,  5,  91. 
Annee,  141. 

Antagonistic  features,  95. 
Anther,  254. 
Apple,  Wealthy,  10S. 
Apples,  bud-variation  in,  1  IS,  175. 
Apples,  hybrid,  06,  79,  111. 
Apples,  races  of,  90. 
Apples,  variations  in,  3,  27,  37,  99, 131. 
Apricot,  bud-variety,  179. 
Aquilegia,  crosses,  224,  229,  234,  239, 
240,  250. 


Aralia,  bud-variety,  180. 
Arthur,  103,  116. 
Arundo,  variation,  176,  180. 
Asexual  propagation,  7. 
Aspidistra,  sport,  180. 
Aster,  varieties,  ISO. 
Atavism,  106. 
Atragene,  184. 
Atropa,  crosses,  223. 
Azalea,  bud-varieties,  ISO. 

Bag  for  covering  flowers,  272. 

Bamboos,  variation,  176. 

Banana,  varieties,  175. 

Bartel,  T.  C,  130. 

Barteldes,  140. 

Bean,  bud-variation,  176. 

Beans,  types  of,  135. 

Beet,  crosses,  56. 

Begonia,  crosses,   224,  226,  227, 

230,    231,    233,    234,    239,    245, 

247. 
Begonia  pollinations,  86. 
Bell-flower,  252. 
Berberis,  crosses,  245. 
Bigness,  variation  in,  1^. 
Blackberry,  crosses,  79,  111. 
Blackberry,  introduction  of.  129. 
Bletia,  crosses,  222. 
Bohnhof,  80. 
Bornet,  232. 
Bouschet,  Henri,  212. 
Brassica,  crosses, 
Braun,  Alexander,  17. 
Breaking  the  type,  19,  23,  93 
Bruant,  113. 
Buckwheat,  crosses,  56. 
Budd,  Professor,  133. 


'J4C, 


239,  240,  241. 


287 


288 


INDEX. 


Bud-variation,  6,  21,  28,  8T,  101,  118, 

126,  153. 
Bugbane,  258. 
Burpee,  139. 
Buxus,  bud-varieties,  181. 

Cabbage,  crosses,  56. 

Cacti,  crosses,  235. 

Calceolaria,  crosses,  222,  229,  233,  234, 

239,  245,  247. 
Calceolaria  plantaginea,  dwarfs,  144. 
Calliopsis  tinctoria,  dwarfs,  144. 
Callistephus  horteusis,  dwarfs,  145. 
Calyx,  253. 

Camellia,  bud-varieties,  182. 
Camellia,  crosses,  251. 
Canary-grass,  crosses,  57. 
Cannas,  140. 

Capsella,  crosses,  226,  231. 
Carman,  79. 
Carnation,  115. 
Carriere,  96,  116,  153. 
Caspary,  229. 
Cedars,  156. 

Cephalotaxus,  sports,  1S3. 
Cereus,  bud-variety,  184. 
Cereus,  crosses,  226,  230,  233,  239. 
Cereus,  night-blooming,  256. 
Change  of  seed,  28,  59,  116. 
Checking  growth,  116. 
Cheiranthus,  sport  of,  1S5. 
Cherry,  hybrid,  112. 
Cherry,  sports  of,  171. 
Chloranthic  varieties,  153. 
Chlorosis,  149. 
Choice  of  variations,  31. 
Chrysanthemum  carinatum,  100. 
Chrysanthemum,  sports  of,  158. 
Cimicifuga  racemosa,  258. 
Cinchona,  crosses,  225. 
Cirsium,  crosses,  229,  233,  239. 
Cistus,  crosses,  219,  222,  231,  234. 
Clematis,  crosses,  224. 
Clematis,  flowers,  262. 
Clematis,  varieties,  1S4. 
Climate  and  variation,  24,  114, 146. 
Coleus,  sports  in,  120. 
Coloration,  148. 

Colors,  modified  by  climate,  25. 
Conifera\  156. 


Contradictory  attributes,  9S. 

Convolvulus  pollinations,  85. 

Coreopsis  tinctoria,  dwarfs,  144. 

Cornus,  bud-varieties,  185. 

Corolla,  253. 

Cotyledon,  crosses,  229. 

Crabs,  hybrid,  66,  111. 

Crata-gus,  crosses,  239. 

Crinum,  crosses,  218,  225,  229,  232,  234. 

Cross-breeds,  Focke  on,  247. 

Cross,  function  of,  50. 

Cross,  primary,  215. 

Crosses,  characteristics  of.  68. 

Crosses,  Focke  on,  215. 

Crossing  a  means,  107. 

Crossing  and  change  of  seed,  59. 

Crossing,  limits  of,  44. 

Crossing,  philosophy  of,  39. 

Crossing,  rule  for,  109. 

Crozy,  113,  140. 

Cucumber  pollinations,  85. 

Cucumis,  crosses,  222. 

Cucurbita  Pepo,  75,  84. 

Cucurbitaceaj,  crosses,  46,  5S,  74,  82, 

229,  230,  235. 
Cultivation,  philosophy  of,  22. 
Currant,  sports  of,  173.     (See  Kibes.) 
Cypripedium,  254. 
Cypripedium,    crosses,   218,    227,  229, 

246. 
Cytisus  Adami,  185. 

Dactylis,  bud-variety,  185. 

Darwin,  17,  23,  32,  42,  47,  51,  54,  56,  60, 

63,  69,  72,  84,  87,  117,  119,  121,  176, 

228. 
Dating  back,  106. 
Datura,  crosses,  222,  223,  224,  226,  228, 

234,  239,  240,  249,  250. 
Decaisne,  229. 
De  Candollo,  150,  178. 
Derivative  crosses,  238. 
Dewberry  crosses,  79,  111. 
Dewberry,  introduction  of,  129. 
Dianthus  Chinensis,  dwarfs,  145. 
Dianthus.   crosses,   21&,  219,  223,  226, 

227,  229,  233,  234,  237,  239,  240,  243, 

244,  245,  246,  25a. 
Dianthus  seraperflorens,  156. 
Dichroism,  154. 


INDEX. 


289 


Digitalis,   crosses,   21s.   219,   221,  '-".'3, 

226,  2-21,  229,  230,  232,  237. 
Dimorphism,  154. 
Dioecious  plants,  260. 
Divergence  of  character,  23. 
Division  of  labor.  42. 
Doubleness  in  hybrids,  237. 
Doubleness  of  flowers,  149. 
Dracaena,  variation,  1 7 * ► . 
Duval,  M.,  16T. 
Dwarfing,  25,  114,  143. 

Early  varieties,  140. 
Echinocactus,  sports,  186. 
Eckford,  113. 
Egg-plant,  crosses.  .r>7,  74. 
Egg-plant  pollinations,  65. 
Egg-plants,  variation  in,  95. 
Egypt,  plagues  of,  40. 
Ela?agnus,  bud-varieties,  186. 
Emasculation,  265. 
Envelopes,  floral,  252. 
Environment  and  variation,  12. 
Epilobium,  crosses,  218,  222,  229,  230, 

233. 
Equilibrium  of  organisms,  20,  61. 
Erica,  crosses,  229,  2:;::.  239,  24i>,  2  til, 

247. 
Essential  organs,  200. 
Euonymus  Japonicus,  156,  1S6. 

Fa-us,  fern-leaved,  187. 

Fall  sowing,  11."..  143. 

Ferns,  crossing-,  277. 

Fertility  of  soil.  18,  22. 

Finis,  forms  of,  188. 

Filament,  254. 

Fittest,  survival  of,  32,  39. 

Fixation  of  plants,  31. 

Flavor,  modified  by  climate,  25. 

Flon,  M.,  156. 

Flowerless  plants,  crossing,  277. 

Focke,  6S,  81,  108,  215. 

Fontanesia,  sport,  188. 

Food  supply,  1<»,  11C. 

Fortuitous  variation,  0. 

Fragaria,  crosses,  229. 

Fiaxinus,  bud-varieties,  1S8. 

Fromont,  158. 

Fuchsia,  crosses,  229,  233,  239,  247. 


Fuchsia  flowers,  273,  274,  275. 
Function  of  the  Cross,  50. 
Fusain,  150. 

Galium,  crosses,  222. 

Gardenia,  bud-variety,  189. 

Gartner,  216,  21s,  219,  220,  228,  233, 

235,  239,  240,  24:'.,  244,  248,  249,  250. 
Gazania  rigens,  140. 
Genera,  monotypic,  97. 
Gesneraeea?,  crosses,  227,  229,  246. 
Geum,  crosses,  219,  229,239. 
Giant  forms,  145. 
Gibb,  Charles,  133. 
Gideon,  Peter  M.,  108. 
Gillyflower,  bud-variety,  1S9. 
Giraud,  Desire,  100. 
Gladiolus,  crosses,  226,  229,  234,  245, 

240. 
Gleditschia  triacanthos,  207. 
Glossary,  2S2. 
Golf,  103. 

Gordon,  229,  241,244. 
Gourd,  crosses,  58,  74,  82. 
Grape,  bud-varieties,  174,  210. 
Grapes,  hybrid,  00,  78,  110,  111. 
Gray,  Asa,  33,  178. 
Greenhouses,  produce  variation,  115. 

Halloek,  V.  II.,  &Son,  124. 

I  lardy  varieties,  145. 

flartogia  Capensis,  192. 

Iledera,  forms  of,  189. 

Ilelianthemum,  crosses,  223,  220. 

Helichrysura  bracteatum,  dwarfs,  144. 

Henderson,  138. 

Herbert,  24S. 

Hibiscus,  bud-varieties,  190. 

Hibiscus,  crosses,  225,  250, 

Hibiscus  Syriacus,  257. 

Hieracium,"  crosses,  220,  233,  234,  237, 

239,  250. 
Hippeastrum,   crosses,   226,   229,   234, 

239,  245,  246,  247. 
Holly,  sports,  191. 
Horse-chestnut,  bud-variety,  178. 
Husk-tomato,  Oo,  85. 
Hyacinth,  forms,  190. 
Hybrids,  characters  of,  68,  215. 
Hybrids,  Focke  on,  215. 


290 


INDEX, 


Hybrids,  multiple,  246,  247. 
Hybrids,  rarity  of,  53. 
Hybrids,  seven-eighths,  243. 
Hybrids,  three-fourths,  243. 
Hybrids,  triple,  244. 
Hydrangea,  146,  191. 
Hymenocallis,  crosses,  230. 

Iberis  umbellate,  dwarfs,  145. 

Ignotum  tomato,  123. 

Ilex,  bud-varieties,  101. 

Impatiens  Balsamina,  dwarfs,  145. 

In-breeding,  72. 

Indeterminate  varieties,  87. 

Individuality,  causes  of,  8. 

Individuality,  fact  of,  2. 

Instruments  for  pollination,  270. 

Ipomoeas,  colors  of  seeds,  104. 

Iris,  bud-variety,  192. 

Isolation  of  the  plant,  22. 

Isoloma,  crosses,  226,  227,  231,  233, 

246. 
Ivy,  forms  of,  1S9. 

Jamain,  M.,  163. 
Jobert,  M.,  179. 
Joigneaux,  M.,  204. 
Juniperus,  bud-varieties,  192. 

Klotzsch,  226,  229. 

Knight,  Thomas  Andrew,  17,  54,  227, 

229. 
Kohl-rabi,  80. 
KOlreuter,  54,  73,  216,  217,  219,  228, 

229,  243,  244,  250. 
Kumerle,  W.  J.,  140. 
Kuntze,  225. 

Labor,  division  of,  42,  48. 
Lachaume,  M.,  166. 
Lactuca,  crosses,  238. 
Ladle  for  pollinating,  271. 
Lamium,  bud-variety,  192. 
Lamium,  crosses,  239,  241. 
Lantana,  crosses,  222. 
Large-flowered  varieties,  145. 
Late  varieties,  146. 
Latitude  and  plants,  25. 
Laurocerasus,  sports,  192. 
Lavatera,  crosses,  234,  239,  243. 


Leanness,  25. 

Lecoq,  227. 

Lemoine,  113. 

Lens  for  pollinating.  270. 

Leptosiphon  densirlorus,  dwarfs,  144. 

Lettuce,  crosses,  56. 

Ligustrum,  sports,  103. 

Lilac,  bud-varieties,  193. 

Lily,  white,  253. 

Lima  beans,  138. 

Limits  of  crossing,  44. 

Linaria,    crosses,    222,    227,   238,   239, 

241. 
Lindley,  68. 
Links,  missing,  41,  48. 
Linnaeus,  SI,  152. 
Linum,  crosses,  223. 
Lobelia,    crosses,    219,   222,   232,   233, 

234,  235,  245. 
Luffa,  crosses,  232. 
Lupines,  heredity  in,  106. 
Lychnis  Coeli-rosa,  dwarfs,  144. 
Lychnis,  crosses,  240,  241. 
Lycium,  crosses,  218,  226. 
Lycopods,  crossing,  277. 

Maize,  crosses,  56. 

Malle,  Dureau  de  la,  175. 

Mamillaria,  sports,  194. 

Maple,  Wier's,  109. 

Meadow,  plants  in,  23. 

Medicago,  crosses,  220,  233,  240. 

Melandrium,    crosses,    220,    222,    223, 

225,  231,  233,  240,  244,  245. 
Mendel,  239. 

Mentha,  bud-variety,  194. 
Mentha,  crosses,  229,  241. 
Mersereau,  131. 
Mimulus,  crosses,  222,  251. 
Mirabilis,   crosses,  222,  226,  227,  22S, 

234,  241,  250,  251. 
Mirabilis  pollinations,  85. 
Missing  links,  41. 
Mixing  in  the  hill,  118,  201. 
Molinia,  bud-variety,  104. 
Momecious  plants,  259. 
Monotypic  genera,  97. 
Moore,  Jacob,  110. 
Morning-glory,  54. 
Morong,  Dr.  Thomas,  00. 


INDEX. 


291 


Morren,  149. 
Mourriere,  M.,  1T5. 
Mulberry,  Teas',  109. 
Multiple  hybrids,  246,  247. 
Munson,  Professor,  58. 
Munson,  T.  V.,  79.  111. 
Musa,  bud-variety,  194. 
Muskmelon  pollination,  B5. 
Myrtle,  bud-variety,  195. 

Nanz  it  Neuner,  lTu. 

Narcissus,  crosses,  220,  225,  236. 

Natal  variations,  15. 

Natural  selection,  32,  51. 

Naudin,  216,  229.  248. 

Nectarine,  origin  of,  118,  173. 

Nepenthes,  crosses,  220. 

Nicotiana,  crosses,  72,  217,  219,  222, 
224,  225,  226,  227,  229,  233,  234,  237, 
238,  239,  241,  243,  244,  245,  246,  250. 

Nicotiana  pollinations,  85,  86. 

Nuphar,  crosses,  226. 

Nymphsea,  crosses,  218,  225,  227,  231, 
234,  250. 

Odoriferous  varieties,  147. 
Oenothera,  crosses,  219.  239. 
(Enothera  Drummondii,  dwarfs,  144. 
Oger,  Pierre,  166. 
Olea  ilicifolia,  195. 
Opuntia,  bud-variety,  195. 
Orange,  bud-variety,  195. 
Orchidae,  crosses,  229,  233,  235. 
Orchids,  hybrids,  79. 
Orontiuin,  sport,  195. 
Osmanthus,  sport,  195. 
Ovary,  255,  263. 

Palmer,  Asa,  139. 

Pansy,  146. 

Papaver,   crosses,  218,  224,   226,   229, 

231,  237. 
Papaver,  forms  of,  151. 
Pare,  M.,  160. 

Parents,  influence  of,  81,  217. 
Passitlora,  crosses,  220,  226,  229,  235, 

250. 
Peach,  bud-variation  in,  IIS,  173,  196. 
Peach,  hybrids,  47. 
Peaches,  races  of,  91. 


Pear,  bud-varieties.  174,  197. 

Pears,  hybrid,  66,  79,  111. 

Pears,  variation  in,  99. 

Peas,  viney,  16. 

Pelargonium,   crosses,   218,   220,  229, 

230,  233,  234,  237,  245,  246,  247. 
Pelargonium,  sports  in,  198. 
Peloric  varieties,  152. 
Pentstemon,  crosses,  241. 
Pepino  pollinations.  S6. 
Pepino,  variation  in,  95. 
Pepper,  red,  pollination,  85. 
Peppers,  variation  in,  96. 
Persica,  196. 
Petal,  253. 

Petunia,  crosses,  21S,  240,  241,  251. 
Petunia  pollinations,  S5,  86. 
Phalaris,  sports,  198. 
Phaseolus,  crosses,  223,  23S,  241. 
Phlox,  bud-varieties,  199. 
Phragmites,  bud-varieties,  199. 
Physalis,  60. 

Physalis,  variation  in,  96. 
Picea,  bud-variety,  199. 
Pink,  156,  160. 
Pinus,  bud-varieties,  199. 
Pinus,  crosses,  226. 
Pistil,  255. 

Pisum,  crosses,  223,  238. 
Pittosporum,  sport,  200. 
Plant-breeding,  91. 
Pliny,  131. 

Plum,  hybrids,  47,  112. 
Plum,  sports  of,  172. 
Plums,  Japanese,  27. 
Podocarpus,  155,  183. 
Pollen,  254,  264. 
Pollinating  kit,  277,  278. 
Pollination,  252. 

Pollination,  uncertainties  of,  83. 
Polymorphous  varieties,  153. 
Polytypic  genera,  97. 
Populus,  bud-variety,  200. 
Populus,  crosses,  222. 
Position,  advantage  ofr  22. 
Post-natal  variations,  15. 
Potamogeton,  crosses,  227. 
Potato,  37,  117. 
Potato  and  tomato,  95. 
Potato,  bud-varieties,  201,  209. 


29: 


INDEX. 


Potato,  seedlessness,  99. 
Precocious  varieties,  146. 
Prin ui la,  crosses,  239,  240,  241. 
Progeny  of  crosses,  237. 
Proliferous  varieties,  150. 
Propagation,  asexual,  7. 
Pruning,  28. 

Prunus,  bud-variety,  205. 
Prunus,  crosses,  229,  239. 
Pumpkin,  crossing,  4('»,  58,  74,  82. 
Pyrus,  crosses,  229,  239. 

Quercus,  crosses,  226,  229,  239. 
Quince,  pollinated,  276. 

Paces  in  fruits,  90. 
Radish  pollinations,  85. 
Eaphanus  Kaphanistrum,  116,  231. 
Raphanus  sativus,  231. 
Raspberry,  flowering,  260. 
Raspberry,  hybrids,  79,  111. 
Representative  species,  66. 
Retinosporas,  156. 
Rheum,  bud-variety,  206. 
Rhododendron,  crosses,  145,  218,  222, 
225,  226,  229,  230,  239,  245,  246,  247. 
Ribes,  bud-varieties,  206. 
Ribes,  crosses,  230,  2:'.:;. 
Robinia,  bud-varieties,  206. 
Rogue,  89,  127. 
Rosa,  161. 

Rose,  bud-varieties  in,  US,  161,  207. 
Roses,  crosses,  233,  247. 
Rubus,  crosses,  227,  230,  232,  234. 
Rubus  odoratus,  260. 
Running  out  of  varieties,  36,  125. 
Russia,  fruits  from,  27,  90,  "133. 
Rye,  hybrids,  79. 

Salix,  bud-varietv,  208. 

Salix,  crosses,  219,  225,  226,  227,  229, 

231,  234,  239,  244,  245,  246,  247. 
Salter,  119. 
Salvia,  crosses,  223. 
Sambucus,  sports,  208. 
Satyrium  hircinum,  14S. 
Scabiosa  atropurpurea,  dwarfs,  145. 
Scalpel  for  pollinating,  270. 
Schizanthus  retusus,  dwarfs.  145. 
Scissors  for  pollinating,  270. 


Secondary  crosses,  238. 
Seed,  change  of,  28,  59. 

Seeds,  colors  of,  104. 

Seeds,  early,  147. 

Seeds,  immature,  103,  147. 

Seeds,  large  and  small,  101. 

Selection  and  progress,  120,  122,  127 

Selection,  natural,  32,  51. 

Self-fertilization,  effects  of,  54. 

Senecio  cruentus,  dwarfs,  144. 

Sepal.  253. 

Seven-eighths  hybrids,  243. 

Sex  and  variation,  11,  43. 

Silene,  crosses,  234. 

Sinningia,  crosses,  231. 

Solanum,  bud-varieties,  209. 

Solatium,  variations  in,  95. 

Spencer,  01. 

Spiraea,  bud-varieties,  209. 

Sports,  22,  28,  37,  153. 

Sprengel,  54. 

Squash,  crosses,  58,  74,  82. 

Squash  flowers,  261. 

Squash,  Hubbard,  46. 

Stamens,  254. 

Stigma,  255. 

Strawberry,  Wilson,  125. 

Struggle  for  life,  20,  29,  39. 

Sturtevant,  103. 

Style.  255. 

Sugar-cane,  varieties,  175. 

Survival  of  the  fittest,  32,  39. 

Swamping  effects  of  inter-crossing,  46. 

Sweet,  247. 

Svmphoricarpus,  sport,  209. 

Symphytum,  bud-varieties,  209. 

Synchronistic  variations,  117. 

Tagetes,  dwarfs,  145. 
Teas,  109. 

Teleology  of  hybrids,  236. 
Thinning.  •_':!. 

Three-fourths  hybrids,  243. 
Thuyopsis,  sport,  209. 
Tillage  and  food  supply,  17,  22. 
Timbal-Lagrave,  217. 
Toad-flax,  152. 
Tobacco  flowers,  266. 
Tobacco  pollinations,  S6. 
Tomato  and  potato,  95. 


ENDEX. 


293 


Tomato,  crosses,  58. 
Tomato,  Lgltotum,  123. 
Tomato,  pollinated,  '-'Til. 
Tomato  pollinations,  85. 
Tomato,  Trophy,  .">T. 

Tomato,  variation  in,  9S. 
Tomatoes,  breeding,  103. 
Tragopogon,  crosses,  238. 
Triple  hybrids,  244. 
Tropaeolum,  crosses,  222,  226. 

rimus,  bud-variety,  209. 

rimus,  crosses,  226. 

Variability,  variation  in,  25. 
Variation  and  environment,  12. 
Variation  caused  l.y  sex,  11,  48. 
Variation,  fortuitous.  9. 
Variation,  philosophy  of,  1. 
Variations,  choice  of,  31. 
Variations,  fixation  of,  31. 
Variations,  natal  and  post-natal.  15. 
Variations,  origin  of,  8,  41.  [157. 

Variegation,    perpetuating,    120,    I4',t, 
Varieties,  running  out,  36,  125. 
Variety,  what  is  a,  35. 
Verbascum.  cros>cs.  219,  221,  222,  223, 
224,  226,  229,  235,  239,  250. 


Verdier,  Victor,  167. 

Verlot,  121,  143. 

Veronica,  crosses.  283,  239. 

Viburnum,  sports,  209. 

Vilmorin,  152. 

Vilmorin,     Henri     L.     de,     100, 

142. 
Vilmorin,  Louis  Leveque  de,  106. 
Vine,  bud-varieties,  1 74,  210. 
Viola,  bud-variety,  210. 

Viola,  crosses,  22!>,  231. 

Vitis.  crosses,  229,  239,  245,  246. 

Walker.  Ernest,  120,  169. 
Wallace,  47.  60.  67. 
Watermelon  pollination,  85. 
Wcismann,  13,  14. 
Wheat,  hybrids,  79. 
Wichura,  216,  246. 
Wier,  1>.  P..,  109. 
Wigandia,  sport,  215. 
Willdenow,  152. 

Yucca,  variation,  176. 

Zinnia,  crosses,  241. 
Zinnia,  flowers,  268. 


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